If you want to apply conditional validation on 'Country Code' or 'State Code', then you need to add 'Country Name' input as 'India'
{{contactForm.controls?.countryName?.errors?.minLength.message}}
Minimum length upto 10 characters.
Shows message from ReactiveFormConfig.
{{contactForm.controls?.mobileNo?.errors?.minLength.message}}
Minimum length upto 8 characters.
Shows custom message.
{{contactForm.controls?.landLineNo?.errors?.minLength.message}}
To apply validation here, write 'India' in 'Country Name' textbox because it is conditional expression.
Minimum length upto 3 characters.
Conditional Expression with type 'string'
{{contactForm.controls?.stateCode?.errors?.minLength.message}}