It is an "invitation letter". Which means you take it to the indian embassy or consulate where you live and can show ID that shows you live there (not "where you happen to be at the current time"), and apply for a visa.

You'd have to convince the issuing officer that you need to get a 5 year student visa of course - and this is normally granted to recognized higher education institutions (as in that award a degree that you can use to get a job, and that is certified by the university grants commission .. aka "not a diploma mill" of the tri-valley university sort that US authorities recently busted)

It depends on whether the consulate officer who reviews your application thinks (and more likely has documentation) that you're applying for a valid course - and what is the curriculum there .. grow beards, drink bhang ..