Most rejections on bank forms come from the pixel size, not the KB. The IBPS / SBI photo preset crops to 200×230 and lands between 20 and 50 KB; the signature preset crops to 140×60 and lands between 10 and 20 KB, padding the file up when a clean signature comes out too small.

For the thumb impression and the handwritten declaration, open the reduce image size in KB page, choose Exact size (crop), and type 240×240 with a 50 KB cap and 20 KB minimum, or 800×400 with a 100 KB cap and 50 KB minimum.

Try it on your own photoDrop a photo at the top of the page. Ten seconds later it's sized, sharpened and ready to post.
Compress a photo