Many composers wrote a 6th symphony. This question is meaningless without knowing which composer.
It's the one by the same composer that was published immediately following the publication of his Symphony #49. Very few composers ever wrote that many symphonies.
bach, beetoven, haydn, and mozart, and vivaldi
Specifically using the name "Classical Symphony"? Serge Prokofiev, who wrote it as a tribute to the classical era composers of the past.
Beethoven wrote many symphonies, including Symphony No. 9 in D minor, Op. 125 "Choral," which was his final symphony. However, many famous composers have written a 'ninth symphony' of some description, therefore your question is entirely too vague.
Every symphony that was ever composed was written by the person who composed it. So the answer to your question is 'every famous male composer who wrote at least one symphony'. How you define 'famous' is up to you.
I believe that Tchaikovsky's most famous Symphony is his last, Symphony No. 6- Pathetique.
Many composers wrote marches. John Philip Sousa is probably the most famous for his marches; he was called the "March King."
Countless composers wrote oratorio's. Probably the most famous is the Messiah by Handel.
There are thousands of composers. One of the earliest was Queen Liliuokalani of Hawaii, who wrote Aloha Oe.
Most composers who wrote symphonies wrote more than one, and the majority don't have specific titles, so simply numbering them was easier.
Many composers wrote 5 or more symphonies, including Haydn, Mozart, Beethoven, Schubert, Tchaikovsky, and Mahler.