Unable to ssh into aws ec2 instances.

Is the EC2 machine in a public subnet or a private subnet?

If it is in a public subnet, can you make sure the security group for the machine allows inbound traffic on the ssh port.

If it is in a private subnet, you cannot connect from the internet. You will need a bastion host on a public subnet or you will need connectivity to the VPC from your on-prem network using either IPSec VPN or DirectConnect