If you are over 50, you can be exempt from the usual age limit in the following circumstances:
If you are nominated as a Minister of Reigion
If you are nominated to fill a senior academic or research position with a government organisation
If you have worked in Australia on a 457 for your employer for at least the last 4 years and you have been a high salary earner for the entire period - the relevant salary level is $133,000 from 1 July 2014