Sole Possession of Ancestral Property by my Paternal Uncle

1. My grandfather (G) was the sole owner of Property A - an apartment (1000 sq ft). His wife (my grandmother died in 1975. 2. G had 2 sons, elder son P and younger son K. G's elder son P had two sons - M & N (me being the younger son, N) G's younger son K had one son - Q 2. G and his 2 sons, elder son P (along with his wife and 2 sons M & N) and younger son K (along with his wife and 1 son Q), stayed together in Property A along with G as a joint family. 3. Also, P and K together were 50:50 owners of Office X (which was bought by G for his 2 sons P & K in their names). K was the sole user of office X and also holds all documents of office X and Property A. 3. K had separately & solely invested in one apartment Property B (700 sq ft) in 2010 (and had financed the same via a Bank mortgage for 10 years loan) 4. P and his family moved out of property A in 2008 as his 2 sons were growing up and needed more space for/after their marriage. They stayed in a property C (600 sq ft) owned by P solely. 5. G died in 2011, K took over sole possession of Apartment A and requested NOC from P for sole ownership of apartment A. In return of this relinquishment in property A, K verbally promised P that he would transfer property B (solely owned and purchased by K) to P as a consideration for giving up his right in property A. 6. P agreed to K's offer and signed on the Transfer Deed of Property A in K's favor in 2013. 7. Now K refuses to transfer Property B in favour of P saying that it is under bank mortgage and transfer deed cannot be done as there is still a loan pending which will complete only in the year 2020. K also refused to sign an MoU prepared by P in 2015 that he will transfer Property B in favour of P after K completes the mortgage loan in 2020. K also refuses P to access Office X and is in sole possession and use of Office X. P wants to lease his portion of Office X but K refuses him to access Office X. P is afraid that K may have influenced and manipulated the society records in which Office X is situated and transferred Office X in K's favour as K has been the secretary many a times in the said society. It seems now K is not willing to transfer Property B to P stating the reason that its under a bank mortgage loan, which K is regulalry paying EMI till 2020. K has also given P a hint that in the year 2020 after the bank mortgage is over, if P wants property B to be transferred in his favour, then P has to transfer his ownership share rights in Office X to K before K can transfer property B in favour of P. 8. P has no documents of Property A and Office X, but wants to take action against K as he has not fulfilled his verbal promise to transfer Property B against the relinquishment of P's share in property A. 9. With the above, please advise what action P can take immediate against K. 9.1. Can P revoke his consent given in the transfer of Property A in favour of K? What can be done to gain the share in Property A or in Property B as per the verbal agreement. 9.2. What action can P take to gain possession of his portion in Office X as he has no property documents with him? Can he write to the society in this regard to get a copy of the documents? Please advise. Mumbai, India.