Even bigger map?!

[bobbin]

Both India and China were completely disunited at the time so his chances might have been good in that respect, Chandragupta Maurya is recorded as saying the Alexander narrowly missed making himself the master of India due to the unpopularness of the Nanda rulers.
Of the two India was the only region he could have conceivably conquered after raising fresh armies, China was too far away and he would have to pass through the territiories of varoius powerful steppe tribes to get there and defend what would be extremely streched supply lines from said tribes as well not to mention having to then fight the Chinese states when he got there.