1.The reasons given by the BPTP are all frivolous to say the least and they are only harassing tou for reasons best known to them.
2.Send them a legal notice to register the proeprty within a timelimit.
3. UIf they sit idle over the issue then file a case beofre the consumer forum.
4.In the consume forum you will get not only the order of registration but also damages and compensation for delay so far caused without any reason at all.
Good luck.