Hi Jay, you should plan for a 10 day Manali-Leh-Srinagar trip. The best time to do this trip is from end of August to mid-October. The places to visit in and around Leh are Nubra Valley, Turtuk, Pangong Lake, Khardung-La Pass and Hemis. Places to visit in and around Srinagar are Dal Lake, Shalimar Bagh, Nishat Bagh, Gulmarg and Sonmarg. Reserve a day for Manali. A day to reach Leh from Manali. Five days in Ladakh. And, three in Srinagar.
You traveling solo so I am aasuming you will be traveling by own car or bike. If you are driving yourself , it will take three days to reach Leh from Manali. You will have to do permit formality es to cross rohtang. First night stay at Key long, second Night at Sarchu and by third evening you will be at Leh. It is advised to stay for one whole resting in Leh. You can see local monasteries and the confluence of indus and zanskar. The hall of fame a war memorial is a treat to watch in Leh. ao 4th night rest in Leh. On fifth morning start for khardung la early and reach Nubra valley by the evening. Stay over night. Thats 5night. on sixth morning depart for pangong tso and reach by evening. here I would say sometimes the roads connecting pangong to nubra gets blocked due to landslide or so. It was blocked when I visited the place. So in that case you will have to have a day spare in your plan. As you will have to go back to leh and then move to pangong. If everything goes well you will be resting at pangong tso on 6th night. next morning start early to reach Leh in time. stay over night at leh. Next day start early and travel straight to kargil and stay over night on 8th night. next day visit kargil war memorial and reach srinagar by late evening. 9th night you will be at srinagar. 10th morning you start for manali and teacher by the night. ao 10th night you will be in manali. keep on day spare to sight seeing at kashmir. I would recommend sonamarg. so in all you need 11nights and 12days to complete the circuit on bike. if you are not driving your own. You will save three days as the drivers will take you directly from manali to leh in one day and leh to srinagar in one day. But then you will miss many beautiful landscapes.
The best time to take this trip will be early august to late september.
I hope it answers your query.