You can certainly watch "The Bad Batch" after "Ahsoka," but it depends on your preference and what storyline you want to follow. "The Bad Batch" is set shortly after the events of "Star Wars: The Clone Wars" and continues to explore the aftermath of the Clone Wars and the rise of the Empire, while "Ahsoka" takes place later in the timeline, following Ahsoka Tano's journey after "Star Wars Rebels."
If you're looking for a chronological experience based on the timeline of the Star Wars universe, you might want to consider watching "The Bad Batch" first, as it takes place before the events of "Ahsoka." However, if you're more interested in Ahsoka's story and character development, watching "Ahsoka" first is perfectly fine as well. Ultimately, it depends on your personal viewing preferences.