Am I not yet grown up to handle a cell phone even after completing 12th standard

Hello Shona, morning. Every parent is different, some let their kids out in the night, some not even in the day. The reason is because they are protective and some times over protective about their children. At your age, they are very concerned about you, and trust me the news they see on tv enflames them about your safety. Maybe you can talk with them as an adult, make them realize that you know how to take care of yourself, how to control yourself in situations and make your "girl" friends come over and have a family diner where you parents get familiar with the type of group you hang out with. That will help in getting more trust, and about the boys. You should probably not give your number out in the public, thats the number 1 reason guys call up. Best of luck have a great day!