There are lot of beautiful trekking in India. It depends on you how many days you want to trek.i suggest you My favorite 3 trek of india.
Small distance 1day :-Triund,McLeod ganj
Medium distance 3day :- Govindghat to Hemkund sahib and Valley of flowers.
Long distance 10days :- zanskar river,chadar trek in Laddak.