In some rough calculations.
Legion is Season 6 Episode 2.
If we count individuals as people or creatures who the crew have met (not aspects or copies of themselves) after the accident - we have:
24 in Meltdown (Thanks Moogle)
15 in Backwards (Also Moogle)
1 in Inquisitor
1 in Camille (2 if you include her husband, but no one really met him.)
1 in DNA (The Psychopathic Curry Man)
1 in Justice (The simulant prisoner)
2 in Polymorph
1 in Bodyswap (The former crew officer who is decanted into Lister's body)
4 - Timeslides is complicated - Alternate future Lister's wife and butler, Thicky Holder, Rimmer's brother Frank and the commanding officers of the Third Reich. Count that as Hitler only. Rimmer technically met Thicky earlier, so he probably doesn't count as new. That's 4
1 in The Last Day (Kryten's replacement - Hudzen 10)
1 in Parallel Universe (While gender-flipped Rimmer, Lister and Holly are the same person, Dog is not Cat)
2 in Confidence and Paranoia (The titular manifestations of Lister's mind)
1 in Waiting for God (The Cat priest - although only new to Cloister)
At least half a dozen in Holoship - though none of them could 'join the crew' without deactivating Rimmer. 8 credited.
There were the Psirens too - notable especially for wanting to eat brains. About 7 of them.
That's 70 in total.
Kryten himself might count too. Queeg being Holly in a mask doesn't. Talkie Toaster was known to Lister before the episode.
Short answer: No, Rimmer was lying while trying to flatter Legion. Maybe if he meant people who the whole crew (including Kryten?) met for the first time. With enough time to have a conversation? That would rule out some of the monsters.
Ultimately it's the rule of Funny over accuracy. On the other hand the Red Dwarf crew have met themselves with incredible frequency (and cheaper than paying guest actors!)
In response to Richard's comment:
20 Humans
8 Holograms
27 Androids (Including wax droids and simulants)
11 GELFs
1 Felis Sapiens
1 Canis Sapiens
2 physical manifestations of Lister's space 'flu.
I just thought - technically Lister gave birth to twins too, the result of the drunken liaison with himself. Who knows what they count as.