Treatment of NPS arrears in form 10E / ITR

I have received salary arrears this year which includes NPS arrears as well.

will i get pr shall i take tax benefit of NPS arrears corresponding to past years in those years in form 10E

or should i take tax benefit of the NPS arrears in this year under 80CCD(2).

also in form 16, my employer has reported only this years NPS under 80CCD (2) whereas NPS arrears are shown under salary

if i show entire NPS (including NPS arrears) under 80CCD(2), will it be a problem as my form 16 has only this years NPS as stated above

Note - This years total NPS contribution including NPS arrears is not breaching the limit of 14% of Basic + DA