Central Board Of Secondary Education [CBSE] — Class 10th unjustified marks

My child is studying in Everwin Vidhyashram for like 10 years and scores well too.
But the 10th class results are extremely poor. But later it turns out many toppers have scored around 385. And it is really unfair how students who have spent day and night just to deserve this low marks...the most surprising thing is other schools have scored like 497, 498. Schools first mark itself is 430 - it means even many students had the potential to score high the board had reduced their marks as it is 'zonal correction'.one zone have scored high and the other have scored less...which is not justified. But we cant blame the school management too. They themselves dont know how the marks got low got even though they have uploaded the original marks of children. I hope this issue gets resolved ASAP