Father's property

Yes she has right in the factory property, because it was property of the father who died intestate.your question is not clear about the relinquish deed?  who has executed it?

A relinquishment deed is as good as a sale deed. The one who executes it in fact 'sells' his/her share in the property that he / she would otherwise be entitled to.

The only possibility of reneging on the deed MIGHT BE to state that the said deed was obtained under duress. I don't think this has been tried so far in courts - but the fact that a parent would not arrange for marriage and dowry of a daughter (unless the relinquishment deed in respect of immovable property is signed by her) is, unofrtunately, not uncommon! But then, how would you prove duress or other forms of coercion since the time lapse (1986-2012) would work against you.

Thanks , Yes  after the marriage the brothers have taken signatures on relinquish deeds  or some other blank papers , without informing about the property. The factory is still in father's name registered.