at level 9, 10d6dmg and 3 or 5 rounds of daze ?
Spell Specialization: "Select one spell of a school for which you have taken the Spell Focus feat. Treat your caster level as being two higher for all level-variable effects of the spell."
Fireball: "A fireball spell generates a searing explosion of flame that detonates with a low roar and deals 1d6 points of fire damage per caster level (maximum 10d6) to every creature within the area."
Rod, Metamagic, Dazing: "The wielder can cast up to three spells per day that daze affected creatures as though using the Dazing Spell feat."
Dazing Spell (Metamagic): "You can modify a spell to daze a creature damaged by the spell. When a creature takes damage from this spell, they become dazed for a number of rounds equal to the original level of the spell."
At caster level 9, a specialized fireball will act as CL 11, which hits the cap of 10d6. If you use the rod, and the target fails the save, it's dazed for rounds equal to the original level of the spell. Fireball is a 3rd level spell, so it would be 3 rounds.
Spell specialization increases caster level while duration of daze from Dazing Spell is based on spell level, which are separate concepts.