grammar school vs state school - college/ sixth form acceptance

Is it true that good colleges/sixth forms accept more students that go to grammar schools, as opposed to state schools?
Obviously, grammar school students tend to achieve better than most state school students, therefore better chance at going to good sixth forms, but what about the ones in state schools who also want to achieve well and go to a good sixth form?
Are the chances of a state school student going into a good college/ sixth form much slimmer than a grammar school student?

Reply 1

nju

If you work hard and get good results, there is no reason why you won't be accepted into a good 6th form/college. Whether you go to a state school or grammar school doesn't really matter

Reply 2

Chipher

You really just have to concentrate on your grades, I know a lot of people outside of my college who worked hard and got into good 6th Form Colleges. There isn't any particular bias.