Can I Connect OVH Loadbalancer to my Kubernetes Cluster from OVH Cloud provider
Yes.
You can follow this guide from OVH in terms setting up your load balancer.
And in terms of Kubernetes you'd either want to create a Kubernetes Ingress exposed on a NodePort, this is a good tutorial for that, or you can also expose your services directly on a NodePort and point your load balancer's backend to all the nodes in your cluster on that specific NodePort.
I would also familiarize with the Services abstraction in Kubernetes.
Yes, you can.
How, on the other side, is not an obvious one. My suggestion would be to make it part of your kubernetes infra provisioning with terraform. Using https://www.terraform.io/docs/providers/ovh/r/iploadbalancing_tcp_farm_server.html you can manage endpoints for your loadbalancer based on instances / hosts provisioned either manually or with openstack provider. That's how I do it on our OVH Kube cluster.