Landlord not paying security deposit and making unnecessary conditions

Dear Team, I had rented a flat in Mumbai with lock-in period of 12 months and rent of 26K. But after 3 months false ceiling of bedroom started showing cracks. I complained the landlord but he did not took any actions. After 15-20 days fell entirely from the roof, fortunately no one was injured. I told the landlord that since he has not taken any actions flat is not in the condition provided I gave a notice of one month. Landlord agreed on the notice. Notice was given on WhatsApp. When I left the flat landlord started making unnecessary issues told that I will not pay deposit. When I told that I will take a legal action, he transferred 40k from his relatives account and agreed to pay remaining amount once the flat is rented again. It had been two months and now the flat is also rented. Now the landlord is making excuses and saying that he will give me a final amount of 60K but only after I transfer back 40k in relatives account. Pls let me know what should I do. Final deposit amount to be received is 74K.