Title Suit against Ancestral Property of grand father

I am five brothers, 2 sisters 1 married and another unmarried. My grandfather died in February 2002, father died in December2005. My Buaaa/aunty has got decreed 1/4 share of ancestral property by Title Suit of 2011 in November 2013 which could be known to us only tomorrow i.e. 5-5-16 by stating that she is karta of my mother died on November2012 and us which is completely wrong statement. The court stated in his order that they have not only served summons/ notices also published in local newspaper, but we could not received or traced or know about these and ordered onesided. In this regard, we would like to know what curative steps could be initiated keeping in view of order on false statement, hindu succession amendment act 2005 cut off date 09-09-2005 (if on/after that father of daughter is not alive, she could not got their share), supreme court order dated 16-10-2015 that HSA Act 2005 is not applicable retrospectively. Kindly advice the action or steps could be taken by us, we 5 brothers are living at different places, eldest is living in Jodhpur, second myself in Delhi, Third in Bangalore, Fourth in Supaul but busy in exams, ladt is studying in class 12 now.