CAN i and how do i get my 2015 tax form back, need to prove for immigration purposes

if you use TT online to prepare return, you can pay to print out a copy.  if you used CD., unless you deleted the .tax2015 file or program from your computer you can open it and print a copy for free.  or you can get a transcript from the IRS website - get your tax record, 

What You Need
To register and use this service, you need:

your SSN, date of birth, filing status and mailing address from latest tax return, access to your email account,
your personal account number from a credit card, mortgage, home equity loan, home equity line of credit or car loan, and a mobile phone with your name on the account.
What You Get
All transcript types are available online
View, print or download your transcript
Username and password to return later