There is not a single provision in the Companies Act which deals with the heading Related Party Transactions, but the provisions of Section 295, 297, 300 etc. in which if a transactions is done between related party they have to follow procedures. For specific related party transactions disclosures it is AS 18 which needs to be looked into.
So in nutshell the provisions of Section 295, 297, 300 and AS 18 needs to be go through for understanding the disclosure requirements of related party transactions.