After downloading the OVA file, you can install and configure the Cisco CSR 1000V using the following resources:
Cisco CSR 1000v is a legacy product, you can still legally download the software for testing and lab environments with a free Cisco account. However, Cisco has officially ended sales for this series and recommends migrating to its successor, the Cisco Catalyst 8000V How to Download the cisco csr 1000v ova download free
You can deploy it, configure it, and run it for 60 days without paying a cent. For labs, studying, CCIE preparation, or testing automation (Ansible, Terraform, etc.), this is perfectly legal and sufficient. After downloading the OVA file, you can install