REGARDING VB 6.0 IN XCODE

No. Xcode does not support Visual BASIC. At all.

One of the few ways to use Visual BASIC on macOS is via the Visual BASIC for Applications (VBA) support within Microsoft Office.

VB and VBA are Microsoft tools and technology, and not widely implemented.

No, I believe the only compiler for VB is Microsoft Visual Studio.

Xcode is really set up for C, C++, Objective C and Swift.