on resume, should we say this ?

I highly suggest against it for a couple of reasons.

1) It probably takes about 30 minutes or less to learn all of the different valuation methods.

2) It may seem pretty toolish to list specific pieces of knowledge you know that might be relevant to the job. If it comes up in an interview, that's great. If not, don't try to push it.

Many people have "assisted in valuation of _ company using _ and _ methodologies" in their resume

I mean, DCF and Comps are pretty simple, its more about how quick u learn than what u know

I think it depends on what you are currently doing. If you're an analyst, you don't need to, just precise the important deals you have been working on and the one you could talk about.

If you are not an analyst and that you're doing something else (corp fin, corp acquisition, ..) you may want to explicitly show that you can do the job so it might be a good option.

Anyway, if you put it, be ready to defend it with at least 2-3 examples. Any question about any bullet point on your resume is fair game.

do not list the valuations you know because everyone else applying will learn them before the interview it doesn't set you apart by any means