BBMP khata transfer on death of my father through a WILL

My father is an absolute owner of a self acquired property, a 2400 Sq Ft land with 2 houses built long time back (Ground & First Floor) in BBMP Limits in the city of Bangalore. My father has total of 4 children, 2 sons & 2 daughters each, all are married & are staying with the respective spouses. He passed away on 06th Sep 2022, & has left a WILL (drawn in 2016, duly signed & notarized, but not registered) states as under in connection with the above Property: a) The bequest of the Ground Floor of the said property will be to his Second Son b) The bequest of the First Floor of the said property will be to his First Son. The common areas & facilities belongs to both the sons & the expenses if any has to be shared equally by both the sons & they can enjoy the property. However if any of the Sons wishes to move out of the above property for whatever reasons & gives the property on rent, the rent received has also to be shared with the 2 daughters, as 50% to son & 25% each to 2 daughters If all the 4 siblings decide to sell the property at a later date, the amount received has to be shared between them (1/3rd each to 2 sons & balance equally distributed between the 2 daughters) Now i am the eldest son & is residing at First floor of the house, my brother has shifted & have given the ground property on rent & is sharing the rent with my sisters, as pre-defined, we 2 sons are not ready to sell the property while my eldest sister is tending towards that, which may not be possible. Under this scenario i would like to know the following : a) Is it necessary that the WILL be implemented through a lawyer b) Is Probate is required for WILL implementation. c) Can the Khata of the said property be transferred in the name of we 2 sons as per WILL, if yes, what is the procedure, Documents required, Is Probate required, should we take help of lawyers for WILL Implementation etc. (If Not what will be the status of the property d) If Transferred, can my sisters raise any objections at any point in future Further the WILL also states transfer of finances between we siblings, which has been strictly adhered as per WILL Request to kindly respond to the above queries With Best Regards, C G V Prasad