Is it a bad choice to resit now?

I’m a current year 12 student taking biology, sociology, and chemistry. Ive not had the best gcse grades to get me to the uni i want so i was thinking is it a bad idea to resit maths, combined science, and English language? I’m not sure as juggling those resists and my ALEVEL subjects may be hard but i really need good gcse grades to get to the unis i want to go to. Please help :’)