Hadoop is a Java-based platform. So, to execute a MapReduce job using a .NET language cannot be done directly as we don't have an exact equivalent of .NET for Hadoop. But the job can be done using Hadoop Streaming.
Hadoop streaming is a utility that comes with the Hadoop distribution. This utility allows you to create and run Map/Reduce jobs with any executable or script as the mapper and/or the reducer.
Here is a link that would help you help with creating/executing a simple MapReduce job with C#: https://martin.atlassian.net/wiki/spaces/lestermartin/blog/2014/07/28/27328520/hadoop+streaming+with+.net+map+reduce+api+executing+on+hdp+for+windows
Also, another option is HDInsight.
Azure HDInsight enables you to use rich productive tools for Hadoop and Spark with your preferred development environments. These development environments include Visual Studio, VSCode, Eclipse, and IntelliJ for Scala, Python, R, Java, and .NET support.
You can go try HDInsight as there are .NET interfaces to HDInsight.
I would refer you this link.