Hello Foram,
The suggestion that Vani gave is widely used in most IT companies. Is your company a start-up?
Another couple of them in-vogue are:
1] An employee can come late if he/she has prior permission from his/her boss for late-stay the previous day. This ensures that the boss is aware of it and has some amount of control of the situation since HR wouldn't be tracking the late-comings on a minute-to-minute basis.
2] Implement some sort of an incentive/award for those who have absolutely no late-coming record, something like what we have in some schools, to encourage latecomers to correct themselves.
And finally, if none of your actions, including any rebukes, work, maybe you need to be tough on him, at least to ensure he doesn't become a wrong example to others later.
Regards,
TS