When you say mercs and India in the same sentence, I also expect the word 'Arsonist' to come up. Comeon people! Arsonists are like UB3R-Grenadiers. They may not be worth 1000 gold for 6 in age 3, but I guarantee you that they are indeed powerful. In fact, they have 12 siege range and 140 siege damage. PLUS, they have great regular attack.
Also Urumis, which are fantastic. I don't think that the shipments you get are large enough to make an impact, but if you ship at least the 7 and 9 + mansabdar they can be great.
Also, of course, there are Jat Lancers. Nothing too special, but IIRC they have a large bonus vs villagers.
Homecity only buildings for India include the Mango Groves, obviously, which are great.
[This message has been edited by FreeLance_FoX (edited 10-30-2007 @ 04:02 PM).]