Hard to find reliable information on these late war Louisiana cavalry regiments, but here is what I have:

7th Louisiana Cavalry-
Organized as the 4th Cav Regt at Moundville on March 13, 1864-though its organization remained incomplete
Reorganized as the 7th Cav Regt in Oct 1864

6th Louisiana Cavalry-
"The exact date & place of organization of this Regt remain a mystery. Several Co’s were added to Lt Col Wm Harrison's Cav Bn, possibly as late as Jan 65, to make a Regt. Some records indicate the Regt existed as early as Sept 64. Whatever the case may be, the Regt saw little, if any, fighting during the war.

Posted By: Alan Pitts 29 May 2006, In Response To: Re: 6th La Cav (Roy Palvadeau)
There's not much known about this command, which organized in some fashion during the final months of the war. Art Bergeron writes, "Most of its service consisted of courier & guard duty around Shreveport & Alexandria." The book to review for this is titled Guide to La Confederate Military Units, 1861-1865.

According to Bergeron's book, the 6th may not have existed as a complete Regt prior to Sept of '64. When it did exist, it was up in the Shreveport & Alexandria area. Individual Co’s may have done work against jayhawkers, deserters & draft dodgers.