Not sure why you keep disparaging Indians on this thread. Second or third time you have brought them up completely unprompted. Projecting much? Are you Indian yourself? Or perhaps Asian? Saw you put down Asian men too in another comment.
There’s no universal sign. There are many men that will just make a move, but there are also many respectful considerate men in tech that don’t want to overstep any boundaries or make a woman uncomfortable.
I would suggest what’s called brinksmanship. You keep escalating ever so slightly and see how he responds. For example, you can accidentally bump into him or touch his hand and see how he replies. If it’s a good response, you can continue to escalate until you find out.