Quota - SC -7.5%, ST 15%, OBC - 27%, E WS 10%

Reservations is not a right. Provisions in the constitution relating to reservations are enabling provisions but not rights. SC in Feb 2020
Vertical reservation is social reservation provided to reserved castes like SC/ST, OBC etc whereas horizontal reservations are reservation within reservation like reservation to female, ex-service man, persons with disabilities etc.

Constitution makes provisions for special treatment of socially and

educationally

backward citizens/ST/SC which would not come under Equality

Reservation even in private educational institutions except minority educational institutions [Under Article 15]
Reservations provided in state services in favour of backward classes if not adequately represented [Under Article 16]

Source of Reservations in Constitution

Source	Reservation for class?	Where
Article 15(4) & 15(5)	SCs and STs	Educational Institutions
Article 16(4)	SCs and STs (ground -backward classes not adequately represented)	Public Employment
Article 330	SCs and STs	Lok Sabha
Article 332	SCs and STs	State assemblies
Article 243D	SCs and STs	Panchayats
Article 243T	SCs and STs	Municipalities
Article 243ZJ	SCs and STs	Cooperatives

Article 15(4) & 15(5)	OBCs (ground -socially and educationally backward classes)	Educational Institutions
Article 16(4)	OBCs (ground -backward classes not adequately represented)	Public Employment

Article 15(6)	EWS	Educational Institutions
Article 16(6)	EWS	Public Employment

Article 331	Anglo Indians (Not valid beyond 2020)	Lok Sabha
Article 333	Anglo Indians (Not valid beyond 2020)	State assemblies

Article 15(3)	Women and Children	Educational and other

Article 243D	Women	Panchayats
Article 243T	SCs and STs	Municipalities
Article 243ZJ	SCs and STs	Cooperatives

Quota - SC -7.5%, S T 15%, OBC - 27%, EWS 10%

NOTE: Article 15(3) explicitly provides special provision for women and children

Educational institutions and others if any (generic provision)

Source is Article 15(4) and Article 15(5), 15(6)(a), 15(6)(b)

Article 15(4) is present since original constitution while Article 15(5) was added by 93rd CAA of 2005
Article 15(1) says that "The State shall not discriminate against any citizen on grounds only of religion, race, caste, sex, place of birth or any of them".
Article 15(4) says that "Nothing in this article or in clause ( 2 ) of Article 29 shall prevent the State from making any special provision for the advancement of any socially and educationally backward classes of citizens or for the Scheduled Castes and the Scheduled Tribes"
Article 15(5) says that "Nothing in this article or in sub-clause (g) of clause (1) of article 19 shall prevent the State from making any special provision, by law, for the advancement of any socially and educationally backward classes of citizens or for the Scheduled Castes or the Scheduled Tribes in so far as such special provisions relate to their admission to educational institutions including private educational institutions, whether aided or unaided by the State, other than the minority educational institutions referred to in clause (1) of article 30"
Article 15(6) Nothing in this article or sub-clause (g) of clause (1) of article 19 or clause (2) of article 29 shall prevent the State from making,

(a) any special provision for the advancement of any economically weaker sections of citizens other than the classes mentioned in clauses (4) and (5); and
(b) any special provision for the advancement of any economically weaker sections of citizens other than the classes mentioned in clauses (4) and (5) in so far as such special provisions relate to their admission to educational institutions including private educational institutions, whether aided or unaided by the State, other than the minority educational institutions referred to in clause (1) of article 30, which in the case of reservation would be in addition to the existing reservations and subject to a maximum of ten per cent of the total seats in each category.

Article 15(1) says not to discriminate. However Article 15(3), 15(4 & 5) , 15(6) ar exception which means that State can discriminate/make special provisions for advancement of

Women and Children
Any socially and educationally backward classes of citizens
OR Scheduled Castes
OR Scheduled Tribes
OR Economically Weaker Sections

Accordingly, Central Educational Institutions(Reservation in Admission) Act, 2006 provides a quota of 27 percent for candidates belonging to Other Backward Classes (OBCs) in all Central Higher Educational institutions. SC directed while upholding this reservation to exclude Creamy layer (advanced sections) among OBCs while implementing the law

Public employment

Source is 16(4), 16(6)

16. Equality of opportunity in matters of public employment

(1) There shall be equality of opportunity for all citizens in matters relating to employment or appointment to any office under the State

(2) No citizen shall, on grounds only of religion, race, caste, sex, descent, place of birth, residence or any of them, be ineligible for, or discriminated against in respect or, any employment or office under the State

(3) Nothing in this article shall prevent Parliament from making any law prescribing, in regard to a class or classes of employment or appointment to an office under the Government of, or any local or other authority within, a State or Union territory, any requirement as to residence within that State or Union territory prior to such employment or appointment

(4) Nothing in this article shall prevent the State from making any provision for the reservation of appointments or posts in favor of any backward class of citizens which, in the opinion of the State, is not adequately represented in the services under the State

(5) Nothing in this article shall affect the operation of any law which provides that the incumbent of an office in connection with the affairs of any religious or denominational institution or any member of the governing body thereof shall be a person professing a particular religion or belonging to a particular denomination

(6) Nothing in this article shall prevent the State from making any provision for the reservation of appointments or posts in favour of any economically weaker sections of citizens other than the classes mentioned in clause (4), in addition to the existing reservation and subject to a maximum of ten per cent of the posts in each category.

Lok Sabha and State Legislature

Article 330	reservation of seats to SC and STs in Lok Sabha
Article 332	reservation of seats to SC and STs in State legislative assemblies
Article 331	reservation for Anglo-Indians in Lok Sabha (Not valid beyond 2020)
Article 333	reservation for Anglo-Indians in Sta te assemblies (Not valid beyond 2020)

Original constitutions says reservations for SC and STs are for 10 years but later regularly amended to extend for further 10 years. Now valid until 2030 [Article 334]

Article 335 provides that the claims of the members of the Scheduled Castes and the Scheduled Tribes shall be taken into consideration, consistently with the maintenance of efficiency of administration, in the making of appointments to services and posts in connection with the affairs of the Union or of a State.

Panchayats and Municipalities

Article 243D - Reservation of SC, ST in panchayats
Article 243T - Reservation of SC, ST in Municipalities
Article 243ZJ - Reservation of SC, ST in Cooperatives

Part 16 - Special to certain classes