Impatiens drepanophora

Impatiens drepanophora Hook.f., Rec. Bot. Surv. India 4: 17 1905. ;

Nepal, Sikkim, Myanmar [Burma], Bhutan, Darjeeling, NE-India (Arunachal Pradesh, Nagaland, Manipur, Meghalaya, Assam), Tibet (Medou, Pamo), China (Yunnan) as per Catalogue of Life;
Fwd: Impatiens for identification. I.chapaensis? Arunachal Pradesh 25.5.17 : 5 posts by 2 authors. Attachments (3)- 1 MB each
Pl. check comparative images at Impatiens

I don't think this is I. chapaensis.
First, balsam floras of Vietnam and India (even NE India) have little in common.
Second, spur of I. chapaensis bends downwards, whereas in your plant upwards.
This way your plant is something around I. drepanophora/ I. stanantha.
I will try to dig deeper when time allows.

After checking FoB I am rather sure that this plant is I. drepanophora as it has spreading, multiflowered inflorescences, yellow flowers with delicate red markings and gland-tipped lateral sepals and mouth of lower sepal.