NO. You cannot put 2015 income on a 2016 return. Those 2015 1099R's belong on your 2015 tax return, and you had better take care of it soon. The window for amending a 2015 return to receive a refund closes on April 15, 2019. If you OWE for 2015, your interest and penalties have been adding up for quite awhile.
You either need to amend the 2015 return you previously filed to add those 1099R's or you need to prepare and file a 2015 return if you have not yet ever done so.
And---are you using 2016 software for that 2016 return you are working on? Each tax year has its own specific software.