Can we make a cluster which is moderately powerful using all free cloud computing services available online like Google Cloud Platform, AWS, Oracle cloud, Microsoft Azure etc.

Can't see why not.
Strap Cloudflare in front, and use their load balancing to multiple hosts or in this case multiple services.

https://support.cloudflare.com/hc/...

@C0D4 thank you buddy
Can you help me in this project ??

@Insomniac-coder
If you don't have a Cloudflare account get one, hook up your dns name servers to point to its names servers and then under traffic, setup load balancing.

It's a paid service, but at $5/month for 2 origin servers (1 in AWS, 1 in Google for example) would be worth a try.