You asked
Is the sony e 35mm f 1 8 oss good for portraits?
Yes, with a caveat. The 35mm f/1.8 is a useful portrait lens, but it's best for environmental portraits that show where someone is, and for small groups. On APS-C it frames roughly like a 52mm on full frame, so it's a little wide for tight headshots. As the portraits guide explains, a 50mm or 85mm-class lens is better for those.
If you want one lens for people, I'd start with the Sony E 50mm f/1.8 OSS. The 35mm makes more sense as a general everyday lens that also takes portraits. It's stabilised and works on APS-C bodies such as the Sony a6400 and Sony a6700. For a broader overview, see Lenses.
Written by Claude from this site's pages.