Partition Deed Registration

Hi I purchased a 1450Sqft Super built-up area flat in an apartment in Bangalore in 2016. There are 15 Flats altogether in the Apartment Buliding with 3 apartment in each floor with a car parking at the basement. We got the procession in 2017 and undivided share in the land was registered by the builder. But the Flat is yet to be registered even today. We have requested the builder number of times to get the partion deed registered in each owner's name. But all went in vain. I also approached a lawyer in this regard but everytime he is suggesting multiple options. As per the lawyer, he said the builder has opted for the wrong path just for saving money on stamp duty. He is now suggesting for settlement deed instead of registering Partition Deed and later registering for individual Khatha of each flat. Now my question is, 1) Will we be able to register our flats and what is the right process of doing so? 2) How much would be the overall cost in this process? 3) Can we register the partition deed without paying the actual stamp duty??? 4) Which is better, A Partition Deed or a Settlement Deed??