What is Carlo Maria Viganò's religious order?
Archbishop Carlo Maria Viganò's was ordained a diocesan priest for the Diocese of Pavia, Italy on 24 March 1968. Being a diocesan priest and not a religious priest, he is not and never has been a member of any Religious Order to date.
In 1973 he entered the diplomatic service of the Holy See and worked at the ...
According to catholic-hierarchy.org Carlo Maria Viganò was ordained as priest of the diocese of Pavia on 24th of March 1968.
So he was a (normal) diocesan priest before becoming bishop and is no member of any order.