Deletion of name

We have purchased a builder property in 2010 on joint me and my brothers and the loan part paid by me in Noida. As per mutual aggrement now I am the owner of the property and bank also give me NOC for the same for home loan and transfer the loan fully in my name. Bank also submit the NOC and original agreement to the builder. When I ask to delete the name of my brother and only my name is showed in the property. Builder ask for some administrative charges which I given to the builder. When I sign the new aggrement there I see some of the clause will change by the builder which was not part of year 2010 original aggrement so I will not signed the documents yet. I have also asked bank that builder changes the clause they clearly stated that its disputed between buyer and builder and bank not come in the picture for the same.So my question is below: 1 - Builder have right to change the clause as per today requirement or it same as my original aggrement. 2- Builder give me new aggrement or supplementry aggrement only for name deletion.3- Offer of possession charges builder showing in the new aggrement which was not showing in the old aggrement there is only mention charges will be paid at the time of possession. 4- what are the role of bank they have not involved in the dispute .they have not asked to builder for supplementary aggrement and not mentioned in the NOC they have asked only they have no objection to delete the name of my brother and I am now the property owner