Yes, Roy was in the 6th installment of the Fire Emblem series
Roy is in the sixth installment, Fire Emblem: Fuuin no Tsurugi.
Roy is the main lord in Fire Emblem 6, only released in Japan
No hes in fire emblem 6
Marth and Roy are both from the Fire Emblem series but are in different games. Marth is in: Fire Emblem: Ankoku Ryuu to Hikari no Tsurugi Fire Emblem: Monshou no Nazo Fire Emblem: Shadow Dragon Fire Emblem: Shin Monshou no Nazo - Hikari to Kage no Eiyuu while Roy is only in Fire Emblem: Fuuin no Tsurugi. He is seen in the secret ending of Fire Emblem: Blazing Sword as well. Also, both characters are in Fire Emblem Awakening, but only are available as add on content
Fire Emblem 6 for GBA or in Japan called Fire Embelm Funnin no Tsurgi or something like that
No. In fact, it's possible for Lyn to be Roy's mother.
Roy is not a playable character in Super Smash Bros Brawl
Marth's girlfriend is Caeda, also known as Sheeda.
No, Roy is not manakete. If Roy's mother was Ninian, a dragon, he would be part dragon, but still not a manakete
They don't appear in any of the games together, but I can tell you which one(s) each one is in.Roy is in Fire Emblem: Fuuin no Tsuruji (Japan only)Marth is in Fire Emblem: Shadow Dragon and two other Japanese Fire Emblem games.Ike is in Fire Emblem: Path of Radiance and Fire Emblem: Radiant Dawn.Hope I could help.
Hes not in it because hes not in the new fire emblem wii game