Please tell me what “ Aaj meṅ Sādhāporasi kā upvās rakhtā / rakhtī hūṅ. Mātra āushadhi (medicine) ke liye jal lene ki anumati rahegi” means in English

It means:

“Today I am observing the Sādhāporasi fast. I will be taking only water, and that too only for medicine if needed.”

A more natural English rendering could be:

“Today I am observing the Sādhāporasi fast. Permission is only for taking water for medicine.”