In English the same word can be a noun, a verb, an adjective and an adverb (or a gerund, an adjective and a participle, etc). In Russian (I don't know how things stand in Hindi) this doesn't work. So, in order to know better how to make up sentences in English we (non English native speakers) want to know how to distinguish parts of speech in English
In this sentence, is "requiring" used as a Participle or a Gerund? Any way to figure this out.
Let's change it a little:
There is a strict penalty for violating the law requiring residents to keep their gardens tidy.
There is a strict penalty for violating the law that requires residents to keep their gardens tidy.
There is a strict penalty for violating the law that requires that residents keep their gardens tidy.
You see that this "ing-word" easyly turns into a verb. A participle is more similar to a verb rather than to a noun (unlike a gerund that is more similar to a noun). So, your ing-word is a participle
(But I'm not a teacher and even not a native speaker, so wait for others' help;-))