Questions regarding separation policy after overseas travel

Hi, I had recently travelled overseas through company. It’s been three months since I have returned and got a really good job offer elsewhere. I am planning to resign from my role. Now the separation policy states that in such a case I can resign before 6 months from the date of return only if prior permission is given for resignation. And I have to serve a notice period of 6 months from the date of resignation. But there is also a clause stating that if I am not able to serve the notice period, I can pay the costs incurred by the company which is calculated on pro rata basis for 6 months. Now the questions are - 1. Is prior permission really needed in such a case or can I resign directly? 2. I can serve three months of notice period and I am willing to pay the amount quoted by the company. Can the company deny that and force me to serve the 6 months notice period? 3. I have a substantial individual performance bonus in my ctc for the current financial year. But the policy states that this will not be paid to me if I am on a notice period at the time of payment. Is there a way to fight for this or do I have to let it go?