Question

what is manual scavenging? is it permitted by the law

Answer 1

Manual scavenging is a caste-based occupation involving the removal of untreated human excreta from bucket toilets or pit latrines, that has been officially abolished by law in India as a dehumanizing practice. It involves moving the excreta, using brooms and tin plates, into baskets, which the workers carry to disposal locations sometimes several kilometers away.[1] The workers, called scavengers, rarely have any personal protective equipment. The term is mainly used in the Indian context only.

The employment of manual scavengers to empty "dry toilets" (meaning here toilets that require daily manual cleaning) was prohibited in India in 1993 and the law was extended and clarified to include insanitary latrines, ditches and pits in 2013.[2]

Answer 2

mostly , manual scavenging is the work done by lower caste (broken) people.
in this they need to clean excitatory products such as human waste, and animal waste as well.

I think it is illegal .