First advice, if you want to find a job, don't bother with PPRUNE, as here you will not find much useful advice, as there are no jobs here!
First RYR only accept first time applications.
No official age limit, but there is an unofficial limit, I have loads of friends who are employed by RYR, and they can all confirm this!
If you want a job, there are jobs, I know of many who have got jobs the last 12 months, you need to be lucky, some have to pay for TR's, connections is what is required, and NOBODY on these forums will tell you the whole truth!