This can be understood from Section 6.4 of the MCI Act, which talks about rebates and commission.

“6.4.1: A physician shall not give, solicit, or receive nor shall he offer to give, solicit or receive, any gift, gratuity, commission or bonus in consideration of or return for the referring, recommending or procuring of any patient for medical, surgical or other treatment. A physician shall not directly or indirectly, participate in or be a party to act of division, transference, assignment, subordination, rebating, splitting or refunding of any fee for medical, surgical or other treatment.

6.4.2: Provisions of para 6.4.1 shall apply with equal force to the referring, recommending or procuring by a physician or any person, specimen or material for diagnostic purposes or other study/work. Nothing in this section, however, shall prohibit payment of salaries by a qualified physician to other duly qualified person rendering medical care under his supervision.”

(Indian Medical Council (Professional Conduct, Etiquette and Ethics) Regulations, 2002)