Are you trying to execute SYBASE.sh (SYBASE.sh), or source it (. SYBASE.sh) ? [I normally source the file => . SYBASE.sh ]
First you want to find the linux login that owns the file, and the permissions on the file:
ls -l SYBASE.sh
Find someone with the password to the linux account that owns the file and ask them to modify the permissions:
# to execute
chmod 755 SYBASE.sh
# to source
chmod 644 SYBASE.sh
If this doesn't make sense, post back here with the output from running:
ls -l SYBASE.sh