1. The Relinquishment of share in the property can only be done in favour of other co-owner/s of the property.
2. In the instant case, the share of 1/3rd each by uncle, aunt and your father can only be relinquished between the above three persons only. Hence Relinquishment Deed can't be executed in favour of brother's son and daughter-in-law.
3. However if your uncle and aunt execute a registered Relinquishment Deed in your father's favour, thereby your father will become sole owner of the property. Afterwards, your father can gift the property to you through a registered Gift Deed.
4. A single Release/Relinquishment Deed will suffice, wherein your uncle and aunt execute and relinquish their individual share in favour of your father.
5. Then your father has to arrange for mutation of his name, as sole owner, in the revenue records, like MR Book, RTC, etc.
6. After this procedure, your father can gift the property to you. Therefore, all the concerned have to visit Sub Registrar's Office more than once, on different days.