Hello geetanjali

To study in any university in Canada you need to clear TOEFL with the minimum marks required, and some universities ask for GRE also but most of them don't.

After that it depends on entrance exam or criteria of the university to take admission, some universities take tests and some universities take admissions on the basis of your application form and your academic career.

There are many new domains likes ML, data analyst, cloud computing, IOT and many more, all of them are equally important in near future, it's better to choose what you find easy and better for you.

I hope it helps