If you are looking for good treks at that time, then you have to understand the fact that treks come in different varieties. I will break them down into 3 for you, Simple, Medium and Hard, based on fitness levels really. I do know a bit about treks near Delhi (the best and easiest city to reach and start off with).
For simple treks, Uttarakhand and Himanchal states have a lot of good options.
They are more or less considered a leisurely activity and can be crowded too. Since these treks do have humans around, the treks can be done solo also!
For a bit more effort, there are some medium level treks in HP and UK (the states). Buni Buni (near Kheerganga), Kasol-Grahan, Sar Pass, Tosh Valley, Chandrashila, Kuari Pass, Rangcha Gali (Drilbu Ri Kora) are the ones that i can recall off the top of my head. about 2 years ago
For difficult treks, you will need to travel into the upper Himalayas. That is actually where all the real fun begins, at least for lunatics like me. Baralacha La (and its variations), Pin Parvati Pass (and its variations), Kanamo Peak/Parang La, Markha Valley, Hampta Pass, Chadar Trek, Roopkund etc. Make sure that you are physically AND mentally prepared for these treks. Mountains can be unforgiving to the unprepared.
There are a lot of good sites from where you can get general info on treks. Try this site for starters, it can help.
The following things are my mantras for good treks, hope they can help you too.
1. Research Research Research. You can never do it enough. It goes a long way, helps reduce costs (well well....) and most importantly, makes you feel confident and ready for the things to come.
2. Fit as a fiddle...sticks? Always be fit enough for the treks. Physical fitness is just one aspect. You also need a good mental fortitude.
3. Buy good gear. I can't emphasize enough on this. Better spend 20 bucks more on a good bag than one that starts tearing midway during the trek.
4. Always listen to Locals. They know more than you. If they say it is not safe, then it is not. Get a guide, talk with locals. It will help you network and get news. Locals = Shepherds, small shop owners, guides, local residents.
5. Buy a good map. Read it, research it, tinker around. Its fun. But more importantly, it will save your life in the worst case, or it will make you look knowledgeable in front of others, best case (brownie points from ladies).
6. Learn survival tricks. There is a lot of stuff out there on this. Just youtube it, its really fun, but also life saving. That Bear Grylls show you just saw might really save your life.
7. Get good rope. Optional for most. For solo trekkers, it goes a long way. about 2 years ago