Can one property registered in the name of karta be transferred to a son?

Brief Facts of case We are a huf comprising of 1 karta, wife, 4 sons and 3 daughters having many immovable property in kolkata. karta died and there was no partition done, wife of karta who is currently surviving member decided not to partition property during her life time. Family split, daughters got married, all sons started staying separately with an mutual agreement that eldest brother will manage the affairs of all the assets in the year 1996 As on 2013, a sale deed was formed in which eldest son along with the karta's wife created a sale deed and sold one property to third party without informing or seeking permission with other sons and daughters. As on 2020 aug, a gift deed was formed wherein another property registered in the name of karta's wife was transferred by a gift deed to the eldest son and the eldest son entered into a development agreement wherein 50% of the property after construction will be sold to developer in lieu of construction costs. no one was informed for the same. During property searching as on oct 2020 we came across the above mentioned deeds questions 1) Can one property originally registered in the name of karta after the expiry be transferred to the eldest son without seeking noc from either or all the sons and daughters? wherein karta's wife was the seller and son was the purchaser and the same property was sold to 3rd party? 2) is it possible to challenge the sale deed which was executed at 2013 or is it time bar? 3) can a gift deed be registered without even one son or daughter be witness to the deed? 4) what is the best possible course of action? 5) if karta's wife is uneducated home maker, states that she has not signed in any property documents then what would be the course of action