 it is all the same whether or not you ask for their forgiveness. even if you were to ask forgiveness for them seventy times allah shall not forgive them. that is because they disbelieved in allah and his messenger and allah does not bestow his guidance on such evildoing folk.
استغفر لهم أو لا تستغفر لهم إن تستغفر لهم سبعين مرة فلن يغفر الله لهم ذلك بأنهم كفروا بالله ورسوله والله لا يهدي القوم الفاسقين