please help me

[simeon]

new Regex("^[0-9a-zA-Z_]{6,16}");
How to generate 0-9 a-z A-Z and "-"  rule to crack  a password 
i thank  
Hashcat   -a 3  md5.txt -2 ?l?d?u -O  --increment --increment-min 6 --increment-max 16 ?2?2?2?2?2?2?2?2?2?2?2?2?2?2?2?2