I have one query related to the 'additional decision parameters' here. In the screenshot below, recipient country is added as in additional parameter. In a similar way I added 'recipient.gender' as a additional decision parameter.
At the target side I am unable to locate this parameter under my rawbox location.
This is another link I got where they have used gender as an additional parameter.
I just tried it myself and was able to get the gender parameter from Adobe Target.
When you select "Add a dynamic Image from Target" in the email content in Adobe Campaign, add gender the same way as shown for the country in the screenshot you shared.
Validate and preview the email. It is important to preview the email so that the rawbox parameter is passed to Adobe Target.
In Target, when you define a rule for the audience or the location, select the rawbox you specified in Campaign. Then in the parameter list you should see the additional parameter you passed. See the screenshots below ("genre" is the name of the parameter I entered in Campaign - because I like French! In Campaign it is mapped to the gender field of the nms:recipients table).