I stay in Thane City Near Malhar Talkies , So you are my neighbour
Deemed Convyance whether your society applied with registrar and then rejected ? Order copy required if so ?
Whether you are prefering appeal against it ?
Can you arrange for Property Card , Survey Sheet of your plot and neighbouring plots , take zerox of Self Index file of that land under RTI , Check whether in that file measurement extract of plot is there . If it is there just take down that no. and apply for measurement certified copy of land . If measurement extract is not there ask officer if measurement extract you can get , old measurement will do . This all You can get it from City Survey Office in Thasildar Office Campus (Mamledar Missal that office go inside straight there is City Survey Office)
Whether you can get zerox of Building and all structure Plan for understanding the FSI calcluation etc. done sanctioned by TMC , Occupying certificate with Plan which may be given with OC. if it is not than CC certificate with plan. I want even that bunglow Plan
The issue has to be sorted who has used FSI where of Land ?
After understanding tehnical papers I would prefer to state further things .
If you had lost deem conveyance and then prefering appeal i want to see papers of it.
(Interim solution I feel you need to change complete approach to the case due to technical reason of all construction. Here word technical not related to legal field . but Architecture calculation as per Development Control regularation , Land details maintained as per Land Revenue Code)
Legal solution - Since the land owner have absorbed FSI of land on his plot too , So plot division is not feasible it can lead to more complexity , Partition under Partition Act may also create some technical problem regarding FSI calculation in future . I feel try to forcefully legally absorb that bunglow in your society , try to make that bunglow holder society member and get conveyance of all property in name of society. Now Bunglow owner will not certainly co-operate 100% So presentenation of the matter should be bit different claiming that bunglow is part of that land and since so many flats sold and there are sufficient members looking at various provision in law make him forceful member of society as well and get deemed conveyance of whole land property on society name . This is solution after thinking from various angles including MRTP , Land Revenue Code, and other various future complication .
I don't see early solution but this solution is only correct solution because if you go under Partition Act then whole FSI calcluation can also get jepodized . Rember Partition act was british era act and Maharashtra regional town planning act 1966 is recent so such problem solution you can not get in old act because it is latest complication due to complexity.
Once he becomes forcefully society member and conveyance taken , then change bye law etc. and take decission of wall in all interst peacefully. Don't fight or waste time because since whole bunglow became society property then in future matter also bunlow holder right will be restricited and he will be only one member of society under Society act.