Trending @Accenture; Discussion on Other offer and Next Step

Hi Folk, I have an offer from Fractal Analytics with 16 Fixed and 2 Variable with 1 as a joining bonus. Current Compensation in Accenture is 10.41 Fixed and 21% variable. I am expecting Promotion in December as told by the manager now. What should I do? Can I buy a Notice period as well? When should I resign as Yesterday got an offer?