Since a mobile phone has become an essential gadget to own, a SIM card that connects you to the network is just as important. It’s not difficult at all to get one in India, as long as you have the right documents for it. Whether you’re an Indian citizen or a foreign national.But Why it's not fixed age bar to get a sim card by every operator like Airtel Provide at 17 Years as BSNL also have 17 Year age bar and Whereas Vodafone-Idea Provide at the age 16.5 and Reliance Jio at 18 Years.Why?

The reason for this high penetration of mobile phones in India could be attributed to a burgeoning young population in the country that is eager to adopt new technology, and the growing middle class capable of spending on consumer items. 

So There Should be a Fixed age bar to get Sim card by every Opertor.