Sale of Undivided Share in Property


Hi, I have a property in Greater Kailash area in South Delhi. It is a parental property and the sale deed is in my grandfather’s name. Later the property was divided equally between my father and my chacha (Mutual Division, No document). It is a 208 sq. yd. property which is now divided in the following manner:
Ground Floor - Chacha
First Floor - With us
2nd & 3rd Floor - vertical partition (Left portion chacha/ Right portion with us)

We are four siblings holding 50% undivided share in the property. I have the possession of 1st Floor and my brother has the possession of 2nd and 3rd (right portion) My brother filed a partition suit to get the property divided in four equal parts and get the first floor vertical division done in the same manner as it is done on 2nd and 3rd floor. Court denied his application and said that either the parties do a settlement or the property will be auctioned. My chacha has no role it in as his part is not in question and his mutation and our mutation is done separately. We had all agreed to four equal shareholders in the property and the same is mentioned in the preliminary decree as well.
My question is that now if my siblings are not coming to any settlement, can i sell my share i.e. 1/4th to a third party and make him party in the case? Also, if that is possible can I also hand over my possession to him i.e. first floor till the time court decides for auction?