That is not recommended.  A high pH cleaning solution is designed to dissolve membrane foulants and scales that are soluble in basic conditions.  A low pH cleaning solution is designed to dissolve membrane foulants and scales that are soluble in acidic conditions.  Neutralizing these cleaning solutions while circulating through the membrane system will precipitate most of the materials that were dissolved back onto the RO membrane surface, rendering the cleaning ineffective.

If you do not have a neutralization tank, you should neutralize the RO cleaning solution in your CIP tank, and drain.  Then fill the tank with chlorine-free RO permeate, circulate through your system to displace more RO cleaning solution from the membranes, neutralize in the CIP tank again, and drain again.  Repeat until you achieve a solution pH between 5 – 9, at which point, you can flush the membranes with feedwater to drain.