Getting high Ping from VPN created from Google Cloud through Outline

I have successfully managed to get good speeds through google peering on all non google sites and services by creating vpn through Outline and using vm instance of google cloud but the ping is getting high revolving around 250 to 300.

Is there is any configuration or way to lower the ping?

And I also tried google stadia, but it is lagging and shuttering, barely playable when the speeds is upto 50 mbps, the issue is because of high ping.

A bad ping (high ping) means that you have a poor connection to a server. All of your quick trigger inputs, no matter how fast, are not going to help you win. This is the problem with having a high ping because of VPN proxies, try to change server location shift between them you might get some close route, nothing much you can do to fix this.