The higher eastern peak is the true summit (Kang Yatze I) although less frequently climbed as it is across a technically difficult knife-edge traverse.
An alternative is to climb the North East ridge then directly up the steep snow face (Alpine AD+/D-).
[1] Approach Route - 6200 meter peak is mainly done from mid-June till September end.
This route climbs up very fast and one needs to rest in Nimaling to acclimatize better before trekking to the base camp at 5000 meters.
Early in the season in June and July can have snow from the base camp itself making the climb more slow and difficult.