Selenium:Validations for mobile number

package regularexpressions;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Mobile {
   
public static void main(String[] args) {
   
    String num="9177791456";
    String form1="[0/91]?[7-9][0-9]{9}";
    //String form1="[7-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]";
    //String form1="0?[7-9][0-9]{9}";
    //String form1="(0/[+]?91)[7-9][0-9]{9}";here wrong as output
    //Pattern p =Pattern.compile("[0/91]?[7-9][0-9]{9}");  
   
    //String form1="[a-z][A-Z][a-z A-Z 0-9 . _]*@[a-z A-Z 0-9]+([.][a-z A-Z]+)+";
    Pattern p =Pattern.compile(form1);
    Matcher m=p.matcher(num);
   
    if(m.find()&&m.group().equals(num)){
        System.out.println("valid mobile number");
    }
    else
    {
        System.out.println("invalid mobile number");
    }
   
}

}