If you want to apply conditional validation on 'Birth Year' or 'Admission Date', then you need to add 'Name' input as 'Bharat'
{{userForm.controls?.name?.errors?.leapYear.message}}
To apply the validation of leap on 'Admission Year' field, then enter the value 'Bharat' in 'Name' textbox
Conditional Expression with type 'string'
{{userForm.controls?.admissionYear?.errors?.leapYear.message}}