Is it possible migrate community from 5.0 to 5.1 or 6.0 and keep license?

Is it possible migrate community from 5.0 to 5.1 or 6.0 and keep license?

  
Hi,

I would like to migrate a community edition platform for development and testing purpose from 5.0 to 5.1 or 6.0 versions but is ti possible to keep my original 5.0 license that allow me to have 75.000 SU's?

Regrads,

Miguel