Sorry, we can't understand your question.....pls explain in detail.

What is the document whereunder settlement was made?

once a settlement is made and registered it can not be cancelled unless their are some deviation from settlement agreement.

when you raise a query you must mention detailed facts of your case .you have only raised an academic query as to whether settlement deed can be cancelled after 10 years by executor . what were the terms of settlement deed ? why has executor waited for 10 years? was it in respect of immoveable property?

it cannot be cancelled arbitrarily by the executor

not able to cancel but need more details about your settlement deed