Hi @abhilash,
to add your own collection of workflow templates you would need to recreate our workflow template api, meaning developing your own template api. We can find some documentation about the process here.
To look into what our template api is returning you can checkout these urls
- https://api.n8n.io/templates/workflows
- https://api.n8n.io/templates/collections
- https://api.n8n.io/templates/categories
If you do that you can set your own template host url using the Environment Variable N8N_TEMPLATES_HOST.
An alternative would be looking into our editor-ui client code that is loading the template workflows, collections and categories from our api. You could inject your custom workflows here if you don’t want to develop your own template backend.