Sec 89 benefit on NPS arrear

Dear Sir

 I am a government employee. This FY government contributed rs 2 lakh of NPS arrear which was not contributed between 2013-2016. Equal 10 % amount was deducted from my salary. This NPS amount is over and above.  My regular NPS contribution

Now since this 2 lakh amount is over and above of regular government contribution it is taxable @ 30%.

 Can I take sec 89 benefit as this 10% government contribution was tax free in previous years.Since it is NPS contribution it will be tax free when added in previous years salary but become taxable as it is over and above regular NPS contribution

    I will be thankful for your guidance