Is the program in secondary memory can be a process?
A process is a technical term that has a well-defined meaning.  You can't just re-define standard terms that have an accepted meaning... or if you do, you should expect it to cause confusion.  My advice is to stick with the standard meaning of this term, and read an operating system textbook to learn what is the accepted notion of a "process".

Wikipedia defines a process as "an instance of a computer program that is being executed".  A process is not some set of lines of code.  A program contains a bunch of machine-level instructions.  (Those machine-level instructions are typically obtained by compiling some source code.)  A process is then a running instance of a program.  The process typically is comprised of multiple resources: some memory (in particular, a region of virtual memory), one or more threads of execution, and some operating system state that is specific to the particular process.

So, no, you can't call "the set of lines of code in secondary memory" a process -- that's not what a process is.  Similarly, when you write "We can call the m lines of code, which are in main memory as process.", my reaction is: no, you can't -- that's not what a process is.