First of all I have to tell you that I love the gear (rod/reel/line/leader) you are using.
Get the following lures and you should be good for most part (surf fishing Chennai):
Cotton Cordel Red Fin Swimmer (Chrome with Black Back, Pearl with Red Head)
Works great from the beach. Get some of the 7" and the 5" ones.
Hopkins 2 oz and 2.5 oz metal lures with bucktail treble.
Yo-zuri Hydro tiger popper (Green mackeral, Red Head).
If you can get some more, then go for a couple of Yo-zuri Mag Minnow in Green Mackeral.
You should do great with this set up. For the most part you should have great fun with the gear you have as the average GTs that you get in Chennai beaches are in 15 pound range. For the ones that are 30 # plus, you might have to go heavy. But I would prefer to use what you are using right now.
BTW, I have a question for you.
How did you get a 8' one piece rod to India. I am about to get a 6.5 feet Shimano S.E. inshore rod rated for 1/8 to 3/8 ounce to throw small jigs. But was wondering how to get it back home?