How to strengthen settlement deed

Thanks Mr Sashi for your advice. So, we have to prepare another Release deed with Mother and other three daugthers that they have no rights in future for the settled property. Is my understanding correct?

Thanks a lot for your advice Mr Shashi

From the facts stated, the property is absolutely vested with the second daughter, if the deed was properly executed and the donee has accepted the gift. 

Thanks Mr Venu for your comments. Yes, we have made a settlement deed from Grand father to Grand daughter (second grand daughther) and the deed was witnessed by the mother. The settlement deed was properly registered in the Registrar office and EC was confirmed flowing from Grand father to the Grand daugther. However, the other 3 grand daughters are not aware of this settlement. This happened 4 years before with all Revenue records changed to her name. Now, to avoid any future disputes, we are planning to get Release from all the other 3 grand daugthers. What is the deed to be executed in this case is the query? Will wait for your valuable advice.

In my understanding, the property belonged to the grandfather and during his life, he could convey it to anyone at his discretion; the legal heirs have only a prospective right in the property left intestate after his lifetime. Now that he has conveyed the property to the second granddaughter, she is the absolute owner; others, her mother and siblings included,  have or  can claim no right share in the property. Of course, the second granddaughter, as the absolute owner can convey it to anyone at her discretion.

Thanks for your valuable time and views Mr Venu