Home loan issue due to some documents

Hi sir, I have applied home loan against my flat which is under construction. Now, builder has all type of mutation, taxes, etc. But his land is now "Danga". As well as my bank lawyer asking supplementary development agreement regarding allocation. I don't know what these things means. But loan sanctioned of other people with some other Banks on same property. Should I change bank? Is the above documents are very critical? Please help.