Hi, unclued,
6dn is indeed REELING : EEL (= Lance, perhaps) inside RING (= group). The definition is “on the dance floor?”.
8dn is a three-letter colloquial word for person inside a three-letter word (reversed) for main ( as in the Spanish Main). The last word in the clue is an extra, the jumbled form being quite hard to find in Chambers. The definition is stays, which is a noun, and nothing to do with corsets. The second letter of the answer is involved in a clash with 12ac.