Article 243D of the Constitution of India deals with the reservation of seats in Panchayats:

Scheduled Castes and Scheduled Tribes
The number of seats reserved for these groups should be roughly proportional to their population in the area.
Women
At least one-third of the total number of seats should be reserved for women.
Chairpersons
The offices of Chairpersons should be reserved for the Scheduled Castes, Scheduled Tribes, and women.
Legislatures
State Legislatures can make provisions for reserving seats or offices of Chairpersons for backward classes of citizens.
Expiration
The reservation of seats and offices of Chairpersons ends when the period specified in Article 334 expires.

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Article 243T of the Constitution of India deals with the reservation of seats and offices in municipalities. It states that:
Seats
A municipality must reserve seats for Scheduled Castes and Scheduled Tribes. The number of reserved seats must be proportional to the population of these groups in the municipality. At least one-third of the reserved seats must be reserved for women from these groups.
Chairpersons
The offices of Chairpersons in municipalities must be reserved for Scheduled Castes, Scheduled Tribes, and women.
The seats can be allotted by rotation to different constituencies in a municipality.

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Article 334 of the Constitution of India states that the reservation of seats and special representation for the Scheduled Castes and Scheduled Tribes in the House of the People and in the Legislative Assemblies of the States will end after a certain period. The period of reservation has been extended several times, most recently to 2019 by the 105th Amendment.  

While reservation is an important tool for social justice, efforts should also be made to promote diversity and inclusion in all sectors. This can be achieved by creating a level playing field for all individuals, irrespective of their caste or community.

EVOLUTION OF THE COMMISSION

Originally, Article 338 of the Constitution provided for the appointment of a Special Officer for Scheduled Castes (SCs) and Scheduled Tribes (STs) to investigate all matters relating to the constitutional safeguards for the SCs and STs and to report to the President on their working3. He was designated as the Commissioner for SCs and STs and assigned the said duty.

In 1978, the Government (through a Resolution) set up a non-statutory multimember Commission for SCs and STs; the Office of Commissioner for SCs and STs also continued to exist.

In 1987, the Government (through another Resolution) modified the functions of the Commission and renamed it as the National Commission for SCs and STs4 .

Later, the 65th Constitutional Amendment Act of 1995 provided for the establishment of a high level multi-member National Commission for SCs and STs in the place of a single Special Officer for SCs and STs. This constitutional body replaced the Commissioner for SCs and STs as well as the Commission set up under the Resolution of 1987.

Again, the 89th Constitutional Amendment Act of 20036 bifurcated the combined National Commission for SCs and STs into two separate bodies, namely, National Commission for Scheduled Castes (under Article 338) and National Commission for Scheduled Tribes (under Article 338-A).

The separate National Commission for SCs came into existence in 2004. It consists of a chairperson, a vice-chairperson and three other members. They are appointed by the President by warrant under his hand and seal. Their conditions of service and tenure of office are also determined by the President.

Source: Indian Polity authored by M. Laxmikanth