Just in case you haven't heard of any Indian Social bookmarking sites, heres some that I came across:

1. www.Indianpad.com - seems to be the most popular with very simple design though sometimes it can get a little confusing.

2. www.Rambhai.com - started by some IIM grad, looks good

3. www.YeaWo.com - again a very simple design, seems to be very new, but the thing I like about it is that it also has a forum (though empty) which in the future could be a nice way to interact with people visiting the site.

There are many more but, these are just the few I can remember of the top of my head right now but, none of them seem to be as popular as their counterparts in the west. On the other hand social networking sites like orkut and matrimonial sites seem to be very popular... does this have anything to do with the way Indians use the internet and what we perceive its purpose to be?

I can tell you two big reason that why they are not so popular.
1. The way Indian surf internet and penetration of internet at Indian homes.
2. The way all above sites are being developed.

I may write a whole lot of story on two above lines but just in short, for Indians, internet is still its very beginning so they social bookmarking is not something which may get encouragement in this stage and type internet penetration. Secondly, all above sites are good but they all are missing something in them and that is the way they are being made. Two above are based on Pligg and last one is on drupal.

Even , eTI has its personal bookmarking site :P..
www.Gyach.com , named as Gyach SB

Btw, having separate forum on SB sites do not make much sense as they already have structure of a community site so .. two discussion place at one site is not a good idea !