Laravel Rule Validation for Numbers

If I correctly got what you want:

$rules = ['Fno' => 'digits_between:2,5', 'Lno' => 'numeric|min:2'];

or

$rules = ['Fno' => 'numeric|min:2|max:5', 'Lno' => 'numeric|min:2'];

For all the available rules: http://laravel.com/docs/4.2/validation#available-validation-rules

digits_between :min,max

The field under validation must have a length between the given min and max.

numeric

The field under validation must have a numeric value.

max:value

The field under validation must be less than or equal to a maximum value. Strings, numerics, and files are evaluated in the same fashion as the size rule.

min:value

The field under validation must have a minimum value. Strings, numerics, and files are evaluated in the same fashion as the size rule.

$this->validate($request,[
        'input_field_name'=>'digits_between:2,5',
       ]);

Try this it will be work

The complete code to write validation for min and max is below:

    $request->validate([
'Fno' => 'integer|digits_between:2,5',
'Lno' => 'min:2',

]);

Also, there was just a typo in your original post.

'min:2|max5' should have been 'min:2|max:5'.
Notice the ":" for the "max" rule.