1) I heard gift deed cannot be challenged unilaterally after 3 years of registration. Is that true? Is what she did illegal ?
I got EC of the house from Registrar office which shows a document number which I thought of using to file a case. But when I tried to get the registry documents using that document number, I am getting the registry documents of some other property. When I ask the Registrar office to give me a copy of the recent registry on my house, they say they dont have any.
You have stated that the your mother executed a gift deed on a Rs. 50 Non judicial stamp paper and it was not a registered document. If that is the case then there is no effect on the gift deed, it is an invalid deed. There fore she ignored the said gift deed and proceeded with the sale of the property to a third party.
The only advantage on your side is that she filed a partition suit and then she sold the property, if at all she had the marketable title then there was no need for a partition suit and after filing the partition suit, she cannot alienat the property on her now.
A registered gift deed cannot be unilaterally cancelled by the donor.
2) Some people in registry office are involved in this . how can I tackle this issue?
I heard Deputy Mayor of my city(who is helping them) has given orders to Muncipal Office to give the buyer mutation, I went to Muncipal Office to request to not give them mutation and their documents are now sent for a case study. There I saw their registry documents which had a Document No. different from the Document No. present on EC. When I tried searching that new Document No. on the goverment website, I did not get any results(though I got results for the document numbers before and after this number)
If you suspect foul play and fraudulent activities in respect of this property, you may first write to the registrar about this, on not getting a satisfactory reply, you may file a suit for cancellation of the sale deed as well as the mutation of revenue records.
3) How can I stop the mutation ? (As they threathened me that they will take control of the house in couple of months)
and how can I know which is the correct document No.?
You have to write to the revenue department about stopping of transfer of revenue records, if they dont respnd, you may file a mandatory injunction suit against the revenue department restraining them from proceeding with the mutation of revenue records till the disposal of suit.
4) Should I just apply for cancellation of sale deed or also apply for injuction and stay along with it?
You may file a suit seeking the proposed reliefs.