Microsoft’s software & development tools (eg. VS 2015, Xamarin etc.) can freely be downloaded via DreamSpark from: https://www.dreamspark.com/Student/Default.aspx.
To get a software as a student, you will follow the steps given below:
Create an account: Have a profile by creating a Microsoft account.
Verify your student status: You can use your email@example.com e-mail address. The domain will verify your status.
Check your e-mail: You will have an e-mail from Microsoft Academic Verification Service, use the given link to complete the verification process.
Download software: You will have another e-mail from DreamsPark. Follow the instructions written in this e-mail to download a software from catalog.