Gifted proporty to my granmum transferred to my dad

Hello all Before I ask a question I would like to highlight that we are a uk based family. When my grandad died 20 years ago all of my grandads proporty was divided over his children(4 daughters 1 son) and wife according to islamic law. During this same time my aunty (all 4 of them) dicided to gift there fathers proporty what they had inherited in india to there mother. They gifted the proporty to there mother in a power of attorney to do as there mother wishes to do it it. Once my granmum had been given this proporty she dicided that she wanted to give it to her son. So from power of attorney she had the proporty transferred to her son. All of the above happened 20 years previously when my grandad died. Now in 2018 one of my aunts is taking my dad to court and saying she wants her proporty back. Is there any way my father may have to surrender his proporty that his mother gave him? My granmum is also died 3 months previously. Thank you for taking the time to answer my question.