This is the 13439th most frequent Russian word.
наличном
"Наличном" means "cash" or "in cash" in English.
Here, the word "наличным" is used to refer to the mode of payment, specifically 'cash'. The form "наличным" indicates the instrumental case used to show the means by which an action is performed.
Я заплатил наличным за обед.
I paid cash for the lunch.
In this sentence, "наличным способом" emphasizes the method of transaction, again referring to cash as the payment medium. It is paired with the noun "способом" in instrumental case.
Возьми деньги наличным способом, чтобы избежать комиссий.
Take the money in cash to avoid fees.
Here, "наличным" contrasts with "безналичным" to delineate between cash and cashless (electronic/non-cash) payment methods. It's in the instrumental case modifying "расчетом".