regex how to define that the rule must be the same -

i searching number in format.

[0-9]{3,6}[\-\/]{1}[0-9]{1,3}[\-\/]{1}[0-9]{1,2} 

is there way how define there should slash/ or colom- ? in other words, option first 1 - , second 1 / should omitted.

yes, can use \1 back-reference. matches same character (or group) first matching group. in case, ([-\/]) first matching group , \1 requires same character.

[0-9]{3,6}([-\/])[0-9]{1,3}\1[0-9]{1,2} 

here example: https://regex101.com/r/mkxnun/1