I am living and working at Abu Dhabi and I want to have a tourist trip to India. My passport is from Greece and is valid until 2020. How long will take to obtain a tourist visa ?
You don't need a visa for India, but can apply for an electronic entry Permit here (called "e-Tourist visa"), which has to be applied for at least 4 days before travel.
You present the E-Mail confirmation you get, as well your passport, at Indian border control.