Suppose, I'm using many .ocx and .tlb files in my VB6 program that are not provided by Windows. Now, If I want to run my program in a PC where these files are not present, should I have to install and register both these types of file to be able to run my program or not.
You will have to distribute the OCX files. However, you probably don't need to distribute TLB files, unless you are using remote COM or passing a User Defined Type from that TLB file via a Variant parameter.