Hello @Ipuvi Mishra
Following tools can be used to deliver Internal Developer Platform
1. Backstage or Port
2. GitHub
3. Terraform & CDK
4. Lot of Python Scripts
5. AWS
6. AWS Code Suite or GitHub Actions
7. Kubernetes & ArgoCD
8. etc...
Additionally, based on the organization needs tools might change to achieve the required outcome. For me following toolsets did worked out in multiple platform implementations..