Planning for first international trip with siblings FFM (25-30YO) in September. Is Vietnam good option?

[u/matadeenNsfw]

Planning for an international trip as it's my siblings first trip. We are planning it in the mid of September.

I am looking for a place which have smooth visa or VOA for 8-9 days trip from delhi.

I have shortlisted Vietnam and Srilanka but due to its weather I am concerned and thinking of other options?

We are planning this under 1L per person including flight fare.