No you can bring in reserves as many times as you want as long as you roll the right intiative check. Also remember, some figures have for example Fring Reserves 20 & Fringe Reserves 30 which all fall under you needing to roll an 11 for intiative. So lets say you have two figures with the same reserves lets say Lobot CLO & Xizor,You cant stack both reserves so you would go with the highest being Lobot's 30 fringe reserves.

Basically each round you have a chance to bring in 1 set of reserves. If you have Recon on your team then you make double init. rolls choosing whichever roll you like. So if between both rolls you get 2 different numbers resulting in 2 different figure's reserves, then you only choose one. Look at it like you are only able to get 1 set of reserves each init. but you can do it every round not just once a game.

& last, Reserves are different than Reinforcements. With Reinforcements you can have mutiple figures on your squad with that, that allows you to automatically bring in the reinforcements amount stated on the stat card after both squads are shown to eachother but before the match begins. hope that helps..

yea you can bring in two sets. but you will have 20 from xizor and 30 from lobot so in other words a guard doid for lobot and a bbsv for xizor

EmperorDragon has explained the answer in Swmgamers, check it out:
"Yes, multiple reserves can be obtained at the same time.

One thing to note: The reserves are two different sets, you can't pool them together for a larger pointed character."

oh god, this applies to me THIS week... shhh, don't tell.... ;) and I just made 3 squads all the while forgetting I should be getting LOBOT...