Can a property transferred through gift deed can be challenged?

Hi, i have purchased a property from a friend(who got this property through gift deed from his mother and her mother got that property from his father through registered will.).my friend are 3 sisters in all, including herself. There a tenant was residing in one portion of their property for last 15 yrs at the current rent of Rs. 5500/-per month. at the time of sale deed, my friend ensured that the tenant will leave the property within 3 months. Now its been 3 years since me and my frend are trying but the tenant is not ready to vacate the property. Eventually, when we have moved to court to lawfully evict the tenant, the tenant is saying that either we should compensate him with good amount to vacate the property or he will ask sisters of the owner(from whom i purchased) to claim their share in the property, And further to take a stay on the property. we have got to know that one of the sister is ready to claim her share in the property. I want to know that whether those sisters can claim a share in the properties even if we have a registered gift deed?? Also, can we still evict the tenant through court?