In how many days I will reach 1500

It's different for everyone. Also 6 hours is a lot, but it depends on what you practice, how you practice, etc.

Also it's common to not improve for many months, then suddenly improve 100 or more points.

Anyway, to answer your question, it's possible for you to reach 1500 in less than 1 year, but that would be very uncommon. Improving 100 rating points per year is not bad. My advice would be to plan on that, so if you do it faster, then you will be happy. If you plan on setting a world record and fail you'll be sad.

OTB or online? Because if you have a few good tournaments OTB, your rating can shoot up drastically. For example, here I am sitting at 1300-1400 online while my OTB rating is 1700 USCF. It all depends, really. Ironically, I am doing better without a coach than when I had one.

OTB

No way

Its FIDE

I am USCF 1297

For what its worth, I am a working guy, with little time to give on training and stuff. Did some tactics watched youtube vids, went from 800 on chess.com when I joined to 1500 in 1.2 yeas.

Have stayed in that range ever since though, got a peak of 1564 in blitz a few months after that. Since then yo-yoing in between 1500 and 1400.

So if you are practicising and have a coach and are starting 300 points higher than the 800 I did, you should get there much sooner.

His tactics are only in the 400s because he’s basically only done five tactics that’s why.

what about the match.

of course friendly

Don't take it seriously mate

You're young, have a coach, and are practicing 6 hours a day. Assuming you are practicing properly, you could do it in half a year imo