Chennai Madras Founded Before Mahabharata?

But the cities , Bangalore and Madras, can not be dated beyond , say about 7 to 800 years.
If these cities have artifacts /sitesdating back to 7000 yeras in the case of Bangalore and a million years in the case of Madras, it is reasonable to conclude,with no records of these cities having been destroyed,that history has been lost in respect of these cities.
A little digging reveals astounding fact in the case of Madras