Namrata is a convention to distinguish strong opening bids. It shows 7-9 tricks in the hand. This will help the responder to determine his bid, pass or go to slam. Either way, there is a possible game and maybe a slam
4 Clubs 7+ strong Hearts and 8-9 tricks
4 Diamonds 7+ strong Spades and 8-9 tricks
4 Hearts 7+ hearts and 7-8 tricks. Weaker than the 4 Cubs opening
4 Spades 7+ Spades and 7-8 tricks. Weaker than the 4 Diamond opening
With a supporting hand, the a slam is possible.