I think that IMR is referring to the quota system whereby low-status groups in India have places reserved for them in colleges, universities, the civil service, and politics. These groups include "scheduled castes" (Dalits/untouchables) and "scheduled tribes". It's part of an effort to counter historical discrimination against these groups by the Hindu majority. It's an extremely hotly contested topic in India, as you can probably imagine.

If you have some free time on your hands, look up Bhimrao Ramji Ambedkar. He was a very cool individual who fought his whole life for human rights for the downtrodden.