I had filed my tax Return with Sprint tax in 2017. This year I am using Turbo Tax. In the last step its asking me 2017-1040NR line 36. How to find my 2017 1040NR form?

You should have a copy saved on your Sprintax account.

Follow this link to return to their site: Sprintax

If you cannot access your account, you will need to request a transcript from the IRS. 

Follow this link: Get a Transcript