Hello Nishi.
The 30% syllabus reduction was a one time measure taken by the concerned authority in the wake of the Coronavirus pandemic. The recent unfortunate turn of events forced the entire country into a nation-wide lockdown due to which it was impossible to physically attend classes and the entire nation saw a stop.
Taking into consideration the future of the students the HRD earlier announced the syllabus reduction so students don’t have to go through a lot of stress.
However, imo NEET 2022 would not follow the 30% reduction policy so it is advised you prepare keeping in mind the full portion and not the revised one.
All the best!!