This is not necessarily a rumour which is in the realm of the impossible.  It is well known that after Bajaj has successfully bought into KTM to the extent of 47% synergies between the two companies are growing.  KTM has designs for the Indian market and all but confirmed a 350cc motorcycle and Bajaj is likely to develop the cheaper sibling of that.  Some are speculating that this 350cc  is actually going to be 375 cc while others are speculating that the twin cylinder will be of at least 400cc because they feel that the existing 200cc will become the base.  Some of the more imaginative rumours are that the existing Pulsar 220 will become the base engine and therefore the new motorcycle could be of 450 or even 500cc.  None of them are unrealistic speculations, but as is usually the case with Bajaj we get to know everything only when the product is actually launched.