Does really 10+2 marks matter in College placements and Sit for Placement cell in OFF campus???

At the time of Boards i got some Anxiety and panic and it affects my 12th marks so badly.... However I got 68% in 12th and 58% in PCM.🥲 Does really 12th marks matter in Placement??? I already applied for Improvement exam but I'm burn out from study again those stuffs and I don't know whether I will increase my marks or decrease.....

How 12th marks affect in placement and become the drawback for me in placement?? Overall it only gives support in taking college but idk what to do??? Suggest me your opinion or Idea??