Is 'Could you please looking into the issue?' grammatically correct? [closed]

The short answer to your question is NO. "Could you please looking into the issue" is not grammatically correct. If you are making a request to someone to do something in the future, the correct way to form an imperative is to use the regular verb stem without attaching any tense to it:

"Will you please pass the salt?" or

"Will you please sit still?"

There are some requests that could be made using a participle:

"Would you mind running to the store?" Note that though English speakers may use this to make a request, they are really asking if the person would mind performing the activity, which is not the same as an imperative.

For your specific case: In the first place, I would use "Will you" instead of "Can you" or "Could you." It is generally better to use "will" when making polite requests. "Can" refers to ability, whereas "Will" refers to the person's own willingness to perform your request.

Either "Will you please look into the issue", or "Will you please examine the issue" would be fine.