Hi,
1. the property is not ancestral property as an ancestral property is something is a property which has remained undivided for four generations.
2. Mr.shivji can dispose his property as he wishes, gift /WILL/sell/release or transfer as he likes.Only the question of legal heir comes after his death.
3. There is no option to ask for an injunction or stay of shivji alienating his share of property.
4. However since there has been no division yet and your father has passed away you can ask for your share as your father's legal heir by filing a partition suit and once you file the partition suit you can ask for an injunction .
against Mr.shivji not to create any third party right in the undivided property .
5. If a partition take place now as per the court order in metes and bounds, the whole property shall be divided to two between shivji and legal heirs of Baidnath (his children/grand children )
6.Mr.shivji can gift or bequeath or release his share to anyone, your cousin, as he can do it to any one as he wishes.
7. legal and equal distribution of his property can take place only if he dies intestate.