Hey Ashu, You can do Chadar trek only in January and Febrauary. And when you will book the tour with any trekking agency, they will give you all details. Happy trekking!!!!
Hello Ashu, Below is the link of an article by Badaeri Deshpande on Tripoto:
https://www.tripoto.com/trip/chadar-trek-frozen-river-trek-4151?ref=mobwapp&source=awp It has all the details you asked for plus, it also gives a clear idea on how you can plan your trip day wise. Also, don't forget to share your experience with us here on Tripoto. We'd love to read about it. Safe travels! :)