sealed box , can i port it

You have, at the most, 1 cu ft per sub sealed now.  The speakers don't have enough air as it is now, much less to go in and take up some of that space by putting in ports.  Don't do it.  Redesign your enclosure.

Here is the Memphis recommendation chart, depending on model of sub.  And notice that for any sub model that the vented net airspace requirements exceed that for sealed...(even when considering that this particular chart includes port displacement in the total size given).

DO NOT DO THIS!!!!!  There's so much more to a ported box than simply drilling a hole and if you do this it's basically going to sound like absolute dog crap. When you're putting together a subwoofer enclosure for a particular speaker or set of speakers, there's a lot to take into account. You have to look at things like driver Qts. Vas, Fs, Xmax, the shape of the port and all the math that goes along with calculating what frequency you're tuning the port to, the natural resonant frequency of the driver, of the enclosure, so on and so forth.

So please, for the love of all that is good and holy left in the world, don't just drill a hole in your box. It's ideas like this that make my job a living hell