I am International student on F1 visa status and Non resident. I have lived in US from August 2014. I have filed my 2015 tax return through turbotax. Is that okay or not?

I have already filed my tax return in turbotax . I want to cancel my tax return .Can you help me with the cancelling process?

No, Unfortunately I cannot. You must amend your return and filed the correct one. IRS states: "If you find changes in your income, deductions, or credits after you mail your return, file Form 1040X, Amended U.S. Individual Income Tax Return. Also use Form 1040X if you should have filed Form 1040, 1040A, or 1040EZ instead of Form 1040NR or 1040NR-EZ, or vice versa. If you amend Form 1040NR or Form 1040NR-EZ or file the correct return, attach the corrected return (Form 1040, Form 1040NR, etc.) to Form 1040X. Print “Amended” across the top."
Please note that Amendment in Turbo Tax is not available until Mid-February. You should not try to amend your return until it has been fully processed and you have received your refund or your payment has cleared.

You can also not amend using Turbotax, as it doesnt support the correct forms