Helm Tiller- Can't start installation process.

I am trying to integrate my on-premise kubernetes cluster to gitlab but I am not able to install Helm Tiller and the error message is not helpful.

Things done till now

1. RBAC disabled
2. No firewall between machines.
3. Using latest Gitlab community edition.

can anyone help me in understanding what the error means and possible cause.

Update 1-

I was using old version(11.0) of gitlab and was getting this error. ssl_client: kubernetes-helm.storage.googleapis.com: TLS connect failed wget: error getting response: Connection reset by peer tar: invalid magic tar: short read

As per https://gitlab.com/gitlab-org/gitlab-ce/issues/48978, i updated my GitLab to the latest version and now i am getting the mentioned error.