Sec. 31(7)

If goods are taken for return like sale on approval or you can say that sales will be considered only if confirmation received than you have to raise invoice before or at the time of removal of goods .

and if you have not raise invoice before or at the time of supply then you have to raise such invoice within 6 months from removal .

Here removal of goods means!?

This time of supply may relate to the job work ,contract work conducted with in six months.
In this case invoice may b issued on that basic.

Removal means when goods are handed over to customer

The job worker/contractor approved that the goods sent or return from that place of location.It means that he removed the present place.The dealer may requested to the job worker that a destination place to remove the same in thier invoice.