I am a biology major and would like to do a conservation related project in India for a few months. For foreigners, restrictions are even tighter. Even so, several students have done productive short term projects in India. Plan to stay for at least a few months. Make sure that you arrive in a India a few weeks before you start work.
Most foreigners face a bout of illness the first time they get here.
Do not try to do too ambitious a project. Post to the nathistory-india mailing list for information. I want to do something to save our fast disappearing wildlife. Although this is one of the most frequently asked questions, there is unfortunately no simple answer. At the very least, I will offer a few words of encouragement.