1. You shall have to file the application for probate before the District Court,
2. For seeking probate, you shall have to pay the stamp duty which will be charged as per the value of the property,
3. Patta is not the evidence of ownership of the land, registered Title Deed/ Probated will or legal heir certificate is,
4. You can get the sale deeds cancelled only through Court orde which you can obtain by submitting your claim of the property with the help of the probated will,
5.First file the application for probate for which your Uncle's wife and daughter will get notice to submit their objection if any and at that time only you will require to approach the witnesses. If they are dead, you shall have to get their signature tested,
6. Without obtaining probate of the will, it is not valid even for a day. With probate, it is valid for life.