In the atom of an element X, 6 electrons are present in the outermost shell. The requisite number of electrons it will accept to attain the noble gas configuration is

In the atom of an element X when 6 electrons are present in the outermost shell, the requisite number of electrons it will accept to attain the noble gas configuration is 2.

Element X has 6 electrons in the outermost shell.

In order to acquire noble gas configuration. Element X requires 2 electrons. Since elements having 8 electrons in the outermost shell attains noble gas configuration.