You may sell of the property subject to your share in it. it does not matter that the partition has not taken place. the person buying your share can seek a partition later on also. the question of consent is immaterial til the time you are selling your share in the property.
Only the coparceners possess the right to alienate the joint family property. The non-coparcener members of the family do not have this authority. The coparceners who have such competence may be classified as follows:
All coparceners as one body
Single coparcener in his personal capacity
The Karta, and
The father.