Is it any G-train from Jie Yang to Guang Zhou instead? How long the time taken and the frequency of the train daily?

From Jieyang Railway Station, there is no bullet train for GZ. You need to go to the Chaoshan Railway Station to take the G-train. There are four G-train from Chaoshan Railway Station to GZ South Railway Station. The trains are G6303/G6302, G6307/G6306, G6311/G6310, G6315/G6314.

The train operates around 3 hours.
If you want to know more, you can seach in the Train Section on this website.