1) The first and the foremost thing before choosing an Internet Service Provider is to check its network strength in that area where you are going to use the internet.
2) Get the network connectivity issues confirmed. Even if your ISP provides a cheap and high-speed internet, if it doesn’t maintain the connectivity most of the time, it’s useless.
3) Test the speed of internet data transfer using speed-testing apps. This way one can confirm whether he is getting what he is paying for.
4) Compare the data prices of other ISPs and try choosing the one with cheaper rates.