can I still update my photoshop CS6 13.0 version

If you mean updating to 13.0.6, see this thread:

https://community.adobe.com/t5/photoshop/how-update-ps-cs6-13-0-to-13-0-6/m-p/6694507#M278572

You may have to contact Customer Support since the Updates page is not working.

Also, do not update to MacOS 10.15. CS6 and its updates cannot be installed there.

Adobe Photoshop went Subscription Only after CS6. There is no upgrade path or permanent licenses anymore. You can get it as part of the Photography Plan, starting at $10 a month for a 1 year commitment.

Here are your options: https://www.adobe.com/creativecloud/photography/compare-plans.html?promoid=9DJJ4N49&mv=other

If you want to have the latest version of Photoshop you can subscribe to the Photography Plan which costs around $10 a month and includes Lightroom and some cloud storage.

CS6 its likely to contain some 32bit code.  Which may make CS6 not compatible with Apples latest Operating System versions.  As far as I know Apple no longer support any bit code. You may need to run an old version of Mac OSX.