What is the maximum RAM capacity, in gigabytes, that I can upgrade my MacBook Pro to?

Welcome!

A couple of things about this question so you can help us better help you in this limited setting:

1) Macbook Pros have been in continuous production since 2006 in possibly as many as 100 variations, and variations do not have the same max RAM nor even the ability to be upgraded at all.

2) We are your fellow end users and can neither see nor touch your computer. We do not know how to give you a specific answer if you've not included your computer's sub-model. Without details only you know, all we can give you are generalities.

Fortunately, sub-model is easy for you to find. For macOS 10.7 "Lion" and newer, "About this Mac..." under your Apple menu always shows the needed information for effective posing here:

Remember, if you have a Retina Macbook Pro, the RAM cannot be upgraded by anyone, not even Apple. Retina Macbook Pros are easy to spot—they do NOT have a built-in optical drive.

tanly wrote:

what is maximum ram can be up grade for Mac OS capilena ?

Laptop/Notebook computer

RAM is solder to to the logic board— so what you got is what it is.

The last Mac with user up gradable RAM was mid-2012 16GB RAM was maximum.