My filter system is leaking, should replacing fix it or I need a plumber?

My question is should replacing these filters pretty much fix the problem or I need a plumber?

We can not answer that for you but you can.

Why don't you try replacing it and find out, unless you have money to burn, then call a plumber. Replacing the filter is the smart thing to do, it should be done regularly anyway.

It has code 11350 written on it. Is that how I identify new filter?

Filter are coded But i am not sure that 11350 is the code for the filter. There is code at the top that is difficult to read but it may be Wheerm

there may be others that are compatible. You should ask whirlpool

As far as the leak goes, you should turn off the valve that supply's water to the filters and remove the filters, inspect the rubber gasket on the filter housing and inspect the filter to see if it is FULL. (clogged) Filters filter so it can get "full" of the stuff it is filtering.

The name on the filter says it is a reverse osmosis filter commonly referred as RO.

these are not normally replaced but back flushed. Identifying the point of leakage we may well be able to answer you but not with the information provided. The RO systems I have worked on use high pressure to force the water through the membrane so there could be a seal that has deteriorated. The label mentions a pre filter if that has been replaced the o-ring seal may have been damaged so identifying the leak , and possibly replacing an o ring would be the proper method.