looks like supreme has sent common offer letter to everyone. whether things written in it applicable to a specific person or not they have just sent it.
there would be no name written in offer letter to whom it is sent for.
flaps 35: if you do caravan rating on real aircraft you need to fly(10 hours) as per DGCA exercises mentioned with sortie wise statement issued by the training academy. if you are going to do it on sim, you would be doing 10 hours sim time. In both the cases you will undergo some hours of ground training and written test. Also I have seen trend of DGCA asking caravan pilots to do familiarization and IR flight in India to get Caravan endorsement so be ready to bear the cost of that as I am not sure supreme is going to take care of it.
I am not sure about local rules but Cyril sounds right so confirm everything about rules regarding getting work permit and other important things for working as first officer on caravan in India before investing any money into it.
with the aircraft expected to arrive in a month or so ( as per supreme) and flying would be done regularly between Mumbai and near by states and airports I dont know if supreme would operate it regularly on N registration but anything is possible.