Regifting a gifted property from brother

Single living brother gifted a property to elder brother on Feb23. But now the elder brother finds difficulty to move around to create & keep the document transferred to his name, decides to gift it to his Son.

1. Is it allowed as per law?

2. Do he need to consider stamp duty for the value of property or simple gift deed value as he is transferring to son (1st Linier relative but become 2nd linier relative to uncle) ?

Thanks in advance.