Oslevel

oslevel command is used to find out the version and maintenance level of AIX

To see the current OS and Maintenance level
# oslevel

 # oslevel -r     - To see the current maintenance level
 # oslevel -s     - To see the current service pack level
 # oslevel -l 4.1.2.0  -  To determine the file sets that are below level 4.1.2.
 # oslevel -g     - To determine the file sets that are later than the current maintenance level
 # oslevel -rq    - To list all known recommended maintenance levels on the system