I am using laravel 5.2 framework for my backend. I wanted to know about how to send OTP to an Android application from my backend. Can I use AWS-SNS or GCM or do I need to use some other SMS gateways. Also I want that OTP message to be sent from my custom ID such as VM-REDBUS. Please help me out guys.
You have to integrate sms gateway to your backend. Which will send sms to your client mobile number.
You can see this tutorial to understand the process of sms verfication.
But for that you have to take mobile number from user as input then with backend you can send OTP messages.
You do not need to do any thing with android device about OTP messages. It should be on backend side. Suppose if you also want to integrate IOS then it would be helpful.
For more information you can see the tutorial also.