Can I file tax returns of last 4 years at the same time? Without Assessments of previous years,how to fill out RRSP deduction limit & unused tuition and education amount?

[ma-bagheri]

I'd like to file tax returns of last four years (2014-2017). However, without getting the notice of assessments of these years, I don't know how to fill out some items. For example, to file the tax return of 2015, I know that I can find "RRSP deduction limit" & "unused tuition and education amounts from prior years" in the notice of assessment of  2014. But, I don't have that one, as I am going to file it now!
I've been a university student in these years and didn't have any income, except for 2014. 

[TurboTaxMary-Ann1]

You can file your 4 income tax returns at the same time, however, some of the figures that you enter such as tuition credits and RRSP limits may be incorrect.  You can use whichever figures you do have available.  Keep in mind as each return is assessed by the Canada Revenue Agency, they will make the necessary adjustments to each tax return to update the correct amounts.