Upvote:1
Okay, I have called to this institution - http://www.indianconsulate.lt/index.php/lt/apie-mus/indijos-ambasada and I have found out that in my case I would need a transit visa.
However, since my trip is in less than 15 days (7th of February, now it is 28th January) and the transit visa could only be issued in 2 weeks or so (I can not do all the paperwork online, I have to fill some papers by hand, send them to Vilnius (Lithuania), then they would send my documents to Warsaw (Poland) and back to me) it takes too much time and it is risky if I would get visa in time.
Therefore I was recommended to purchase India tourist visa (e-visa) here: https://indianvisaonline.gov.in/evisa/tvoa.html and that will work for me.
I will probably choose the shortest period that I can get for this visa, since I don't want to pay a lot (planning to spend only 4 hours in Indian airport...). Or, of course, I can sneak a trip to India as well during my visit to Nepal since I will already have an Indian visa. ;)
Anyway, hope it helps someone.
Have a nice trip!