Hi Yogesh
It will get very strenous if you include Kheerganga in the places mentioned and you'll end up spending a lot less time at the places you have planned. I would suggest to choose between either Tosh or Kheerganga. The starting point of both these places is almost the same. Kheerganga is a 10 km (one way) trek, so if you have a decent pace and reach by afternoon, odds are you'll have to spend the night there and come back the next morning. Tosh, on the other hand can be accessed comparitively easily. Let me know if you have any further questions.