Even if you don't have a legal heir certificate and have no objection in distribution of the property then you have to provide relinquishment deed in favour of your mother so that the property can be transferred in her name without raising the question of will.
after the death of your father the property goes to all the first class legal heirs in equal share and in case of will the property could be transferred to one person as stated in the bill in case you want to go by the will then you have to witness in the court that you don't have any objection to transfer the property in your mother's name