How do I make Malog fight me because I have done 'Origin of the gray prince' quest so he just stands and ask me to kill him and that counts as 'MURDER'.

I have no Frenzy Spell.

I don't believe you can at this point, by doing that quest he doesn't care to live. Only way around it is with a frenzy spell (I think, not sure actually) or load to before you did the Origins quest and then don't do it.

It was the First quest I did. SO can't load that now

Yeah then no sorry, you don't have any other choice.

How Do i get the Frenzy spell?

You will have to find a Spell tome with it or buy it from one of the Mage's I believe and make sure it is strong enough for whatever level he is. For what it is worth his death shouldn't give you a bounty.

his death doesn't give me bounty or any Infamy rather it initiates the message 'doing seen by unknown forces' and counts as a Murder nothing else.

Should I proceed with that?

Or is there any way to clear the Murder

That message will pop up when you have your first 'murder' and is required to join the Dark Brotherhood. Since you said you want to join them in your other thread I would say just go with it. Probably the only way to get a murder without it being an actual murder in the game.

I will join them When I make a new Character.