Firstly you have to get NOC from Delhi, you could use the bike without registering it for the period mentioned in NOC 6 months-1year. After 1 year you will have to pay life time road tax here in Chennai which is around 9% of the vehicle cost.
I got this info from a local RTO agent and in my case (R15) he told that total expense involved in the entire process would be Rs 12,500
.
Could someone from Chennai give more info in this context