This question has been asked of me more than once :)
Marathahalli ->
Take Old Airport road ->
Take right at HAL junction .
Left at Old Madras Road ->
Go straight till and around Ulsoor lake till you pass the MEG military quarters on the left , then continue until you see a biggish circle (actual traffic island circle ).
Take right here.It's - this will take you to Cantt Railway station - About 100 m _before_ cantt railway station you will see a masjid after an underpass on the LHS.
Take right here to Nandidurg Road which merges with Jayamahal Road in Front of Fun World/Palace grounds(about 2-3 km).
Continue straight past DD Kendra to Mekhri Circle.
Straight from Mekhri circle until you reach Yeswantpur circle.(you will pass IISc as you go along).At IIsc gate it is a Y-junction -
At YPR circle you can follow the road on the up to reach Platform 4,5,6 or take a right to enter yeswanthpur market and then go to the other entrance which leads to Pf 1,2,3.
There is some construction going on so you might need to go around a bit.At this time you will see yeswanthpur Police station on the left.
The downside of this is that you have to pass a crowded market.Otherwise go up the bridge(DON't take left to go to Rajajinagar), continue about 1.5 km further and take the first U-turn to reach the entrance to platform 4-5-6.
This is a more dignified-looking entrance.If you want to reach Pf 1-2-3 then it's a walk over a rather high overbridge.
