Hi Sherwin,
Sure, the default setting from mojoProfile.config is:
<add name="Gender"
type="System.String"
allowMarkup="false"
labelResourceKey="GenderLabel"
lazyLoad="false"
requiredForRegistration="false"
allowAnonymous="false"
visibleToAnonymous="false"
visibleToAuthenticated="true"
visibleToUser="true"
editableByUser="true"
regexValidationExpression=""
validationErrorResourceKey=""
onlyAvailableForRoles=""
onlyVisibleForRoles=""
defaultValue=""
includeHelpLink="true"
>
<OptionList>
<Option value="" TextResourceKey="GenderUnselectedLabel"></Option>
<Option value="M" TextResourceKey="GenderMaleLabel"></Option>
<Option value="F" TextResourceKey="GenderFemaleLabel"></Option>
</OptionList>
</add>
By changing only the requiredForRegistration t true, it shows up for me on the Registration page.
Hope it helps,
Joe