I was thinking of buying a Canon EOS Rebel T6 to start of with DSLR. Is it a good option? Previously I have used Canon EOS 1200D and Nikon D3300 from some of my friends. And also should I buy the f/1.8 prime lens simultaneously? I want to click some portraits as well.
The EOS Rebel T6 is a good option considering its low price. It is an entry level DSLR so if you are a beginner it should suit your needs.
Moreover given its low price you can afford to invest in a 1.8 prime lens to complement the kit one(if you are buying it). You will have to choose which focal length you want to have. The first 2 options that come in mind are the 35mm and the 50mm, if you want to shoot portraits the 50mm is obviously better.