Section 9(2)(k) in The Securities Contracts (Regulation) Act, 1956
(k)the regulation of the entering into, making, performance, rescission and termination, of contracts, including contracts between members or between a member and his constituent or between a member and a person who is not a member, and the consequences of default or insolvency on the part of a seller or buyer or intermediary, the consequences of a breach or omission by a seller or buyer, and the responsibility of members who are not parties to such contracts;