Hi there !
March / April is perfect time for trekking in the Himalayas. Since your title mentions India and Nepal, I suggest you Goa, Golden triangle of Delhi, Agara and Jaipur en-route to Nepal. May be Nepal first and then visit these classic sightseeing places in India with Goa as final destination to relax.
Regarding Nepal, You can do Langtang Trek, Ghorepani - Ghandruk trek (Annapurna) or Tyangboche Trek (Everest) for about a week.
If you do Ghorepani - Ghandruk trek, you can take the base of Pokhara city as a relaxing place after the trek.
apart from the well known places in India (delhi, agra, jaipur, varanasi, udaipur, goa, kerala), some of the offbeat places that I would recommend is to head to the beaches of Orissa. They are not your regular beaches with hordes of crowds but are definitely peaceful and clean with majestic views. This is my personal experience. Another place that I suggest you can visit for your India trip is the Andamans. No words to describe this place!
Hi I'm planning to visit nepal between 11 march-12 april. Does anyone want to join me for some trekking or meditation stay?
Although If you could not find any one to join with you from here, you can find many people who want to join trekking here in NEPAL. But You should arrive NEPAL before someday of your trekking starts. And join the team. If you want to join others team, you may also consult with local agencies so they can arrange the team for you.
Have Great Time In NEPAL.......
Best Of Luck For Your Trekking......
Ask The Nepal