If still builder is not taking any action regarding your matter you can move consumer forum against the builder for deficiency in service . Builder is compel to furnish plans duly sanctioned by municipal corporation . If he fails to do so you can file RTI application and obtain copies of sanctioned plans .
HI, I am surprised what were you doing till now these are the things which you should ask before the possession. Does not matter If you have a apartment association contact with them and ask why it has not been happened till now and what is the reason behind it? Your apartment association will ask with the builder regarding this matter.