Hi,

I moved from india to usa (texas) on L1 visa for 1 year. I have International Driving Licence. I want to buy used car for year.

I want to know
1. Is it possible to drive car for one on IDP and can I registered the car on IDP or will it required Texas driving lincence.
2. What is the process of Insurance for used car.

I can only answer #2. you just call an insurance company (you may want to call around to a few to get the best price). You'll have to tell them things like what kind of car, what year it is, the VIN #, what mileage is on the car, and how much you plan to drive it. Some of the popular companies are Allstate, State Farm, Geico. If you Google "car insurance" you'll find plenty more.
Hopefully someone else will come along soon to answer the rest of your question.