Hi Akshay,
By default, out-of-the-box schemas are only accessible with write permissions for operators with admin rights.
You can still modify the system filters of the out-of-the-box schemas which are by default protected due to compatibility issues with older versions:
Note
However, Adobe recommends you do not modify the default parameters to guarantee optimal security.
Create an extension for the concerned schema or open an existing extension.
Add a child element <sysFilter name="<filter name>" _operation="delete"/> in the main element to delete application of the filter under the same in the origin schema.
If you like, you can add a new filter, as detailed in System filters.
Thanks,
Ayushman