Inheritance rights in a property dispute with multiple wills

My mother willed her property to all her four children equally in a hand written will with proper witnesses. My brother refused to accept the will saying he has a will of a later date and has taken possession of the immovable property and has also been collecting the rents on the basis of the will in his possession, the original copy of which he refuses to submit in the court on one pretext or the other. We have already submitted the will that we have in court. After my mothers death my brother has started collecting rent in the name of his son on the basis of the so called later will,according to which, allegedly, my mother has bequeathed everything to his son. My question is, can he legally collect rent in the name of his son without any probation of the will he has, by the court? Earlier my mother was collecting the rent. We already have obtained a stay order on the property. Secondly, some of the tenants have vacated the property. Can he rent it out again to new tenants, thereby creating third party rights, in spite of the stay order?