Yes, a business analyst could transform to Data Analytics with ease, business analytics involves more inclination towards business and data analytics involves more statistics and mathematics.
Both professions have similarities between them and one could transition from one to another. On this note, I would recommend you to take up the Data Analytics Course online provided by Intellipaat which is co-created by IBM and is a 92hrs online instructor-led training with 224hrs for projects and exercises to gain more hands-on experience.
Also, do check out our YouTube video on Business Analyst vs Data Analyst from our experts to help you gain more insight.