Well, this depends on what you like to pursue is it between these two fields, or is it anything else other than these two? You should have the answer to this, anyway, I will give you an intro to these two fields.
Big Data Analytics: Big Data Analytics is the study of extracting insights from a very large data set that cannot be handled by conventional methods of processing.
The insight gained from the Big Data is used for the benefits of the organization and to boost its revenue.
Whereas Machine Learning is all about machines learning by themselves on a given data set and processing the information without needing a human intervention only with the help of algorithms that are fed to them.
Machine learning finds its usage in decreasing the workloads of Data Scientists and analysts and in many industries around the world to help these professionals to produce excellent results with zero margins of error.
Are you an aspiring Machine learning expert? Then check out the Machine Learning course from Intellipaat!