By the term "cleaning" I assume you mean a proper cleaning, not some snake pull device or just a dry patch down the barrel. That assumed, and stated, here's something to ponder.
You are in better luck than most, as you are shooting a 6BR which is VERY forgiving in the cleaning department and regiment. However, this assumes you have a decent barrel with a good interior finish. I am speaking from experience, with tens of thousands of rounds of 6mm bullets down the barrels of six 6BR rifles over the last 17 years or so.
Truth be told, on average, the 6BRs shoot their best at about 20-45 rounds -- maybe 55 rounds down the tube.
Good advice has been shared with you to clean after you are through with your shooting session for the day. Why clean when it is still shooting well? Fair question. Answers are numerous, but the primary reason is to avoid the build up of perhaps three bad culprits that steal accuracy and barrel life: 1) chemical reaction from dirty barrels and environmental conditions like humidity 2) carbon ring(s) 3) "excess" copper build-up.
How often you clean it depends upon what degree of accuracy you are looking for. In my experience, for what's it's worth, is most folks don't clean their barrels very well, others try to clean well, but wear themselves out and waste an abundance of cleaning materials, and too many well-intended souls make the most elementary and costly mistake when they begin cleaning their rifles. What is that mistake? Simple. They forget to cover the riflescope lenses before the cleaning session.
Whew! I am glad you didn't ask what's the best way to clean your rifle. You would want to throw it away as everyone told you their way -- the only way -- to clean a rifle properly
Enjoy your 6BR, you have a most excellent cartridge to shoot and clean up after -- especially if you use H4895 powder. Uh-oh, did I say that? Yikes, now others will weigh in with their favorite best powder; but they would be wrong
Stay safe and shoot 'em straight.