Why is Gabriel present in several Angelic orders.?

Gabriel is generally termed only an archangel, but the expression used by St. Raphael, "I am the angel Raphael, one of the seven, who stand before the Lord" and St. Gabriel's own words, "I am Gabriel, who stand before God", have led some to think that these angels must belong to the highest rank; but this is generally explained as referring to their rank as the highest of God's messengers, and not as placing them among the Seraphim and Cherubim.

Gabriel is also placed differently in several other choirs, check below:

The listing as per individual persons and their versions places Gabriel in more Angelic Order than in your question

St. Ambrose

St. Jerome

Gregory the great

Dionysius the Areopagite

Constitutions of apostles

Isidore of Seville

Moses

Maimonides the Zohar

Maseket Azilut

John of Damascus

Berith Menucha

Dante

The Magus Barrett

but I do not suppose it still answers your questions as to why he is placed in so many Choirs, good luck with your search.

You forgot Dominions. But where does it say that he's anything other than an archangel? One of SEVEN that surround the Throne of God. And no, we don't know all of their names. We only know Gabriel, Raphael, and Michael that I am aware of.

Oh, and of course, Lucifer was once an archangel, too.

There are different takes on it everywhere, no one knows the true order. I personally believe him to be one of the four Archangels.

Where did you get this information. It is wrong.