As there is no agreement has been entered between you both, you may object to his deduction of 10% of booking amount and if he refuses to accept your request you may make a complaint against him with RERA.
Real Estate (Regulation and Development) Act, 2016 is going to complete a year and people are still skeptical about the implementation of the provisions of the act. One of the vital point which was not covered under the provisions of RERA was the refund of the booking amount as on the basis of same the home-buyer can’t get the status of an allottee as per Section 2(d) of the RERA Act and for the maintainability of the case a complainant should be an allottee.
Lately, the Maharashtra Real Estate Regulatory Authority in its ruling shed some light on the refund of booking amount as in its order the authority directed the developer to give back the amount of Rs 1 lakh which was paid as a booking sum by the home-buyer.