Cancellation of registered sell agreement in sub registrar ofc

We have done sell agreement in December-2019 of 4 months time period. Between time buyer has not done balance payment ans refused to buy property after 6-7 month. In agreement clear mentioned that after 4 month it will be cancelled and token amount not be refunded. Still agreement was noy cancelled. As of now i have new buyer want to purchase my property. As per online property card his name is not there. As oer my knowledge after registration in property card it is showing of buyer name in property card as non title owner. Now buyer want 50000 rs for sign in cancellation of agreement. In this case what can i do please advise. 1- i have to go for legal action. If yes what action to be taken 2- can i do direct selling to another buyer 3- after selling to another buyer he can do any legal action against me 4- is there any provision to do any documents and submit in sub registrar ofc direcly without his sign 5- another buyer is ready to purchase property within 1 month of time in that period can i closed old matter Thanks in advance Vipul Jadav