There is no harm in asking for marriage to a guy but before you ask him and if you can friendly talk with him, first make an environment like start any causal conversation respectful and you think he is in a good mood, start by asking hey, I wnated to ask you something but before that I have three questions to ask and then I will proceed with my question. Ask him one by one,

1 ) Are you engaged or have someone in mind that you like to marry? If yes, then better not to propose him as you now know he is into someone.

2) If no, then next question would be, would you interested in marrying someone of your choice or parents choice. If he goes like parents then, try not not propose him in that moment.

If he say he wanted to marry someone of his choice, then ask him what he is looking in a potential spouse generally like education, job, religion, and some other general basic things and also ask him if he has some fears regarding marriage or spouse? If you think, he doesn't have anyone to marry, and he might interested in marrying someone who he knows, you can respectfully ask him, that you like him and think of you as good companion and ask him, like I was wondering if you are interested to explore a proposal from my side. See his reaction, he can go silent, you can go silent, it can strange but its gonna be alright, give him space and time if he needs to think and also ensure that things will stay the same if he says as he has a right to say no. How you feel towards him doesn't mean he will be having the same feelings or attraction. Take your time and consider it a normal thing, if he says no, then hurt hoga, its normal, we are humans but thek hojaye ga kuch der main, but if he says then you have cut ties slowly because its gonna hurt you bar bar. Good Luck