Anyway, they are legal. You can import them and pay a huge customs duty on it and no one will bother you.
Right now, some bikes above 800cc have got a few exemptions (that is hoiw Yamaha has been able to bring the R1 and the MT-01 to India). the 800cc limit was based on Harley Davidsons who dont have bikes below that capacity. There was that bikes for mangoes deal abt a couple of years back.
US wanted Alphonso mangoes and in return they wanted permission to export bikes to India. So, they set the limit to 800cc (which was very stupid).
And in the end, no HD bikes came to India. They scrapped their plans saying the duties are very high. So, only bikes above 800cc can be homologated and sold in India comfortably.
If they reduce the limit to 500cc, then it will be an absolute bonanza. we can get the 600cc bikes into India at a very affordable price.