Raju,
You'll want to check out the
Apache Upgrades sub-forum, which has instructions on flashing to WM6.1 ROM in the stickies at the top of the forum (there are two packages to choose from). The instructions use the BuildOS tool which imports the correct carrier ExtROM, and it even includes an ExtROM for Reliance India, so you won't have to acquire it separately. TouchFlo can also be cooked in at the same time... As a total noob myself, I found it suprisinly easy to upgrade my stock Apache from WM5 to WM6.1 and customize it with the applications I desired... These folks have done a phenomenal job around here!
G^2