Promoting

Dear Sir, I have a small house in a plot measuring 3 cottah in Kolkata. Recently I have approached few promoters for promoting as I am unable to maintain my house. My neighbors whose house is just adjacent to my house also desires to give it on promoting (measuring 2 cottah). Therefore, total 5 Cottah to be given on promoting after amalgamation. Now there are certain problems which I would like to seek your advice 1. As per BL & LRO (Sonarpur) record out of 5 Cottah area 3 Cottah showing "Pond" & 2 Cottah as residential plot 2. In the original deed of mine and neighbor (purchased from same owner) there is mentioning of "Sulahnama" with an another person but there is no copy available of this Sulahnama. Further, BL & LRO shows that the land belongs to this person who has lost the case in Baruipur Court and a Sulahnama is issued. 1. My question is whether construction can be done as the Parcha showing "Pond" although it can be hardly recognized now. 2. Whether Sulahnama is sufficient enough to go ahead. This sulahnama was made 55 years back. Therefore, can a copy be obtained and what is the process. 3. Can there be any dispute in future (Specially during construction stage?) Please help Regards, Rajat Goswami