Very few hot-swap cases in DIY scenes are available in India, and almost all are from Silverstone. Another example is this-SilverStone CS280.
If you're open to options other than hot-swap, there are many options. You could modify any decent case to fit as many drives as needed. (20 HDDs example)
Most budget option starts from something like Thermaltake Versa H21 and goes up to dual system cases like Phanteks Enthoo Pro 2, or roomy cases from the Fractal Define series.
You could also use something like this Hard Drive Back Plate and modify any multiple HDDs case and call it a day.
IMO get a budget case and mod it for hot-swap and spend the rest on the drives.