Abhijit welcome to BCMTouring, with regards to itinerary you can do the following (assuming you are starting from Delhi):
Day 1: Jalandhar - Delhi
Day 2: Manali - Sarchu
Day 3: Sarchu - Leh
Day 4: Leh (get the permits and get the bike serviced)
Day 5: Leh - Khardung La - Nubra Valley
Day 6: Nubra Valley - Leh
Day 7: Leh - Tso Moriri
Day 8: Tso Moriri - Tso Kar - Pang/Sarchu
Day 9: Pang/Sarchu - Keylong
Day 10: Keylong - Manali
Day 11: Manali - Delhi
In case you can't add another day, you can do this:
Alternatively you can do
Day 8: Tso Moriri - Tso Kar - Sarchu
Day 9: Sarchu - Manali
Day 10: Manali - Delhi
On the first and last day you will be riding for over 550kms (assuming you are starting from Delhi). For details regarding the route, please go through the guide and you will get all the info you need.
As for the info you requested via PM, well there is no need to carry 3-4 tubes, 2 (1 front and 1 for rear) would be more than enough and there is no need to carry spare petrol for the 180s. On second thought, just carry a pepsi bottle filled with petrol for the Leh - Tso Moriri - Manali stretch.