Yes, India is the most highly populated democracy in the world.

Yes, India is a democratic country.  I included some data below from Wikipedia along with the link to the article.  Warning, Wikipedia can sometimes be incorrect or out of date.  There are many other website offering data on the Indian Government.  Simply search for terms like "india" and "government" or "india" and "Democracy" and see what you get.  Hope this helps.
 
"Democratic India is a free country; vote from any place, specific seats are given out for Scheduled social group and scheduled tribes (22%) in parliament called (reserved voters), in local body election a proportion of seats are given out for women candidates. There is also a proposal to give out 33% seats in all elections to woman candidates, at this moment there is no agreement how to apply it and which seats should be given out. The Election Commission of India is responsible for performing free and fair elections."

yes ,INDIA is democratic country.

yes