Builder asking for 60,000/- as NOC charges after 7 years

I am buying a flat no. 101 in Vedshree Heights, Building Type HC 45, Near Ever shine city last stop, Vasai East, 401208.
We have made the agreement on 22/11/2021. Seller has purchased the flat from builder in the year 2013, since then the society has not been formed. It means builder hasn’t handed over the construction. While buying seller said meanwhile our process, society will be formed and will get NOC from society itself. So we don’t have to go to builder for NOC. Since so many months society is not yet formed, now my housing finance company is asking NOC either from builder or from Society. Seller has approached to builder for NOC and he demanded for Rs 1lakh, then he came down and asked for Rs. 60,000/-. As per the norms written in agreement society transfer or NOC charges should be bared by seller and buyer equally. As because of builder has not handed over the building we need NOC from him only. So I have to pay the unnecessary charges of Rs 30000/-. I clearly told seller that I will pay whatever usually society asked for i.e. half amount of Rs 25000/- now he is also not agree to rest amount.
What should be done in this case, please suggest. The details of builder are as follows:
Name :- M/S. Shree Ganesh Builder and Developers

Siddhesh
Palghar 401208, Maharashtra
Email: sxxxxxxxxx3@gmail.com