So Guys, Am back.
I took the routes suggested here.
Bangalore - Krishnagiri - Tvmalai - Thirukoilur - Panrutti - Kumbakonam.
Thanjavur - Thiruvaiyaru - Ariyalur - Perumbalur - Attur - Salem - Bangalore.
Krishnagiri to Thiruvannamali route is bad. Full of patches guarantee you a bumpy ride and way too many potholes.
Tvmalai inside is horrible... No roads at all and had to crawl till we reach Thirukovilur road. From there to Thirukovilur, is the best stretch. Super smooth roads you can easily do 120. Knda like Hassan - Belur stretch . Thirukovilur to Panrutti is good. Smooth roads mostly, patches and potholes do come now and then. Entire stretch, we have to be very careful of these potholes.
Route back is quite good. Thanjavur to Perambalur, mixture of good roads with patches and potholes. From Perambalur to Attur, route is mostly very smooth, seems to be relaid recently. BUt again, need to be very careful of the potholes. they do appear quite often.
Worst stretch, Attur to Salem. 4 laning going on.. Horrible stretch. Very few smooth roads, full of bumps and not nice at all.
Btw, the NH7 is becoming quite bumpy. The left lane of thoppur ghat section towards Krishnagiri has very become very bad. My car kept moving towards the right lane there... dunno, a u shaped bend is there alll throughout in the ghat section
the SHs though were beautiful to drive on.
hope it is helpful to all