I have used almost all of the mobile operator in my life. Some of them impressed me enough to stay with them a long time, and some of them were so disgusting that I couldn’t use them more than a week.
MTNL is one of them. I started using MTNL back in 2013, because one of my friends recommended. The call rates were relatively low and they were giving some great night offers. But after a week I realized that I had made a huge mistake. Not only their network was poor, there were a lot of cross connection. Once they even deduct my Internet balance of 30 mb. I was so furious. If you work in restaurants or shopping malls, it is highly unlikely that you will receive any calls or be able to call anyone. I got rid of this sim after 2 weeks.
I wouldn’t recommend MTNL to anyone.