Hi Namit,
Me and Saurav last year had cycled to Yelagiri from Bangalore. We
started at 12:20 and was there by 7:30 in evening. It was awsome to
climb-up in dark with our torches on.
The view from the road on the way up was too good. It is steady and
easy climb (as compared to Nandi) .. around 8 Kms.
You also have YHAI as a stay option there. You can also reach at the
base by Train ... just get down at Jolarpettai .. and you are at the
base of the hill :) ... 15Kms ride and you are at the top.
~Ravi