As suggested by Mr Karthik chances are to move in RAC are good but I have doubts by checking the high wait list in Genral Quota in 3A from Mumbai Onwards & keeping the summer factor in my mind. 3A wait list is difficult to clear in summer season than sleeper.
So I will advice you to try tatkal for confirmed tickets, this train is having 30 seats tatkal quota from pune.
If you get confirmed tatkal then cancel this one.