if the state government announce that the public exam for 10th is cancelled will the nios 10th exam will also be cancelled?
The State Education Ministry/Department is responsible for the exams of respective State Board.
NIOS is a separate national level board and such announcements by State Govt. will not mean that NIOS exams also will be cancelled.
For NIOS exam dates/updates, stay tuned to the home page of their official website where all latest news and notifications are posted.
You should consider that NIOS class 10 exams are cancelled if and only if it is also posted in the above link.
Hope this helps.