Is it possible to get the assembly code for TI Intrinisics available for TI C64+ DSP processor?

In general, I think the intrinsics map directly to inlined instructions.  Usually each instrinsic maps to a corresponding instruction from the ISA.  See the Programmer's Guide for more info.

One experiment you can do is write your program of interest, removing or stubbing out the instrinsic call, e.g.:

#include <c6x.h>

int main(void)
{
    int arg1 = 1;
    int arg2 = 2;
    //int arg3 = _add2(arg1, arg2);
    
    return 0;
}

Generate the assembly output (in CCS, project properties > Build > C6000 Compiler > Advanced Options > Assembler Options > Keep the generated assembly (.asm) file (--keep_asm, -k)).

Set aside that .asm.  Now add in the intrinsic of interest, e.g.

int main(void)
{
    int arg1 = 1;
    int arg2 = 2;
    int arg3 = _add2(arg1, arg2);
    
    return 0;
}

Now generate that .asm.

Compare the two, and you'll see how the intrinsic modified your program.  In this case, it basically added an ADD2 instruction (although there is more to it than that).