Search for password with at least one upper/lower and between 8-12 characters.
grep '[[:upper:]]' /usr/share/wordlists/rockyou.txt | grep '[[:lower:]]' | grep -E '^.{8,12}$'
grep '^[[:upper:]]' /usr/share/wordlists/rockyou.txt | grep '.*[[:punct:]].*' | grep '[0-9]$' | grep '^.\{21,\}$'