how do i install photoshop 6 on pc without disc drive

>>>new pc does not have disc drive

You can buy an external USB disc reader for around $30.

1 - CS6 will not work with Mac Catalina

2 - Two ideas that MAY work to install and/or run old programs in Windows 10
-RIGHT click the program icon or EXE and select a compatibility mode in the pop up option window
-and/or select Run as Administrator to assign FULL Windows permissions
-also https://helpx.adobe.com/x-productkb/global/create-local-administrator-account-windows.html

Adobe has removed ALL public download links for serial number programs
-links are ONLY available to someone who purchased a download from Adobe
.
For serial number programs you may download ONLY if you bought direct from Adobe via download
-Log-in to your account and click this link https://account.adobe.com/products
--click Order history on the left and then the link to your order that will show on the right
--and finally click the link "Downloads and serial numbers" that will appear
---as always, write the serial number in a text file AND copy that text file and the
---download file(s) to an external drive (or two) to be sure you have what you need
-if you did not buy direct from Adobe via download you must find your original install
-if you have an Education or volume license you MUST use your original media
--the link for an Education or volume license download is not available at all
-if you bought a disc and don't have a drive you will need to buy an external USB drive
-if you bought and lost a disc Adobe does not provide a replacement via download
-if you bought a download from a 3rd party vendor you will need to contact that vendor