Hi, I'm sorry to say this. Peripheral neuropathy caused by diabetes is irreversible. Means all the peripheral nerves which are damaged now, can't be repaired with any medication. Tablet Nuerobion forte is nutritional supplement to delay the process of damage to remaining nerves. Continue this medication. Your father cannot walk confidently because he cannot feel the pressure or sense his feet to balance his body. It takes time to get adjusted to this new change. Help him to walk by holding his hand. Hope this helps.