Opinion Related To Probated Will Of GrandFather

Hello All, I need legal opinion on a personal matter. Family Tree - GrandFather 2 Sons (Elder Son Expired - 2 Daughters) (Younger Son - 2 Sons) 3 Daughters My grandfather has executed a unregistered will way back in 1997 on a self acquired property to his grandsons. He expired in 2000. Upon his death we have submitted the will for the probate order in the lower court of Patna. This was under trial till 2007 and eventually we have acquired the Letter of Administration. During this trial this will information was shared in a news paper and there was no objections from the Elder Uncle & His 2 Daughters. Having said that the court has given the 3rd party judgement and given the letter of administration. Now in the year 2014 my elder uncle's daughters have challenged the letter of administration. Please be noted that my elder uncle is expired now. My lawyer is not telling me that there is a chance that the judge will give judgement in the favor of my cousin sister's in view that my grandfather was forced but this isn't the truth for sure. Need Your Legal Opinion - If this LOA challenge by my cousin's sister has any legitimate right. Thanks!