Clarification

Respected,

I have a clarification, please clarify it for me.

Where and when and how can we use "Present perfect tense and Passive voice for past tense".
I came to know the basic functionlality of these sentences But my doubt is these two sentences are seems to be same in terms of meaning. In which situation on what basis we shoud use these senteces.

Ravana was killed by Rama (Passive voice for past tense)
Ravana was killed (Passive voice for past tense with out Object)
Ravand has been killed(Present perfect tense )
Ravana has been killed by Rama(Present perfect tense )
Rama killed Ravana.(Simple Past tense).
Ravana got killed by Rama ........ is this correct structure?

As far as I know these sentences are grametically perfect, but my question is when and where and on what basis we should choose the sentence structure.


Please clarify this for me.



It would be better if you could give some some examples in this regard.

Please correct me If i am wrong, I appreciate your help.

Thanks in Advance.

Regards

Madhu