Is the sentence, "It is raining still now", correct ?
Can "still now" be used to mean "even now" ?
Or will it be "It is raining still",
Yes, but not common
or, "It is still raining".
Bingo! Yes, correct and common.
Still is used to say that something is in the present, not the past... it has not finished, but we are surprised that it is not finished.
"She is still asleep... I thought she would wake up an hour ago."
"You are not still friends with Suzy, are you? I thought you did not like him."