How to use "SQL(ROW_NUMBER())" as same as for ElasticSearch Query using C#?

Thanks for your reply.
We have create search functionality in E-Commerce site, and we have create one index in ElasticSearch.
It's having 2.5L record. It takes a long time when I run a C# MVC code.
Can you please guide me how we can get faster result using C# MVC?
Is there any way to sync fast and easily transfer data from SQL to Elasticsearch?