It is not currently possible to cycle from India to Thailand via Myanmar. Nor is it possible to enter Tibet from Nepal as an independent tourist. Cycling in Tibet requires accompanyment by tour guide and vehicle, which cost 4500USD for thirty days, as of last summer. Tibet may be closed to foreigners without notice, as was the case when I tried to arrange my trip last summer. I was cycling west in China, and ended up diverting to SE Asia and finished my tour in Singapore.