According to article originally, a Special Officer called Commissioner for SCs and STs is appointed for constitutional safeguard of SC and ST to submit a report to President 

In 1978, a Executive Resolution is brought for a Multi member Commission for SC and ST (non-statutory body)

In 1987, the above commission is renamed as National Commission for SC and ST with modified functions 

In 65th CAA 1990, High level multi member Commission 

In 89th CAA 2003, bifurcated the Commission for SC(Art 338) and ST(Art 338A)

Chairperson 

Vice Chairperson 

3 other members 

To investigate and monitor all matters relating to constitutional and  legal safeguards for SCs and evaluate their working 

To inquire into specific complaints with respect to deprivation of rights of SCs

To participate and advise on the planning process of socio-economic development of SCs 

To present to President, annually and at such times as it may been fit, reports upon the working of those safeguards 

To make recommendations as to measures that should be taken by Union and State for effective implementation of those safeguards for protection, welfare and socio economic development of SCs 

To discharge such other functions in relation to the protection, welfare and socio economic development of SCs as the President may specify 

President puts it before the houses of Parliament 

President also forwards any report pertaining to State Government to Governor and he puts it before the Legislature 

Commission while investigating any matter or inquiring has all powers of civil court in respect of following matters 

Central and State Governments are required to consult the Commission on all major policy matters affecting SCs

Commission is also required to discharge similar functions with regard to OBC and Anglo Indian Community as it does with SCs and report to President upon their working