Yes Rajesh, though TN was really late to the party, this is still a very good news.
But, this tax sop is for the manufacturers who are manufacturing in TN. So it’s left to the manufacturer to pass on the benefits by cutting the cost. Tax rebate to the manufacturer is not quantifiable. So I am not sure if the manufacturer will pass all the benefits to the consumer or price it according to the market demand and competition.
Because, direct benefits like FAME subsidy, Road Tax Exemption, Registration Fee exemption are directly passed on to the consumers…
I assume if Ather starts manufacturing in Chennai, the final price of Ather 450 would have gone below the 1 Lac barrier… 
EDIT: I realised Road Tax Exemption is confirmed. Now, over to Ather to start manufacturing in Chennai and pass on the benefits to set the market on fire.