Nepal is one of those few countries where Indians don’t need a visa. The borders are fairly transparent with free movement of citizens on both sides. All you need is an identification proof that proves your citizenship. A passport, voter’s ID card or other nationally accepted identification document works. At the immigration section, they just take a scan of your identification document and let you go through. And you can stay as long as 2 years inside Nepal and sometimes even more. Yesterday, I came through the immigration counter at the Tribhuvan international airport in Kathmandu and they didn’t even stamp my passport. I was let in after a quick scan of my passport. As an Indian traveler, this is a rare experience and hence I totally loved the special treatment.
So, if you planning on trekking in the Himalayas or exploring other parts of Nepal, you don’t have the visa stopping you.