Hi Priya ,
If you are going for to enroll for a 1 year course you can surely write JEE 2011 and if you are able to get a good rank and make it to a desired college you can go for a 4 year course .
But before going for preparation you should set your aim on which college and what stream you want to go for so that you can raise up your preparation level .
You can check out free sample papers and study material available on ASKIITIANS.COM and also enroll for a free demo for online class so that you have a slight idea.
Feel free to post as many doubts you have we wud be happy to help .
All the best !!!