What are the chances to find Giovanni outside of timed research?

So i would like to ask few things, google did not gave me an answer. 1) Can Giovanni spawn again via rocket radar? And if yes, will he have Groudon or someting else? 2) How does the beating leaders before him work? In timed research i had to beat them all before him, but now after winning, leader takes my rocket radar. Thanks for any help :)