I have offers from the aforementioned universities. QMUL one is a specialisation in Human Rights law while the other two are General LLM offers. I'm quite interested in the areas of International Maritime law and also Human Rights law, so kindly suggest me which one of the three would be a good choice for the two areas of law mentioned.

Although these are all strong schools, none stands out particularly above the pack for either maritime law or human rights law.

Generally speaking either Edinburgh or QMUL has the better ranking, depending on if you're looking at the Guardian or the Complete University Guide.

I'd suggest looking closely at the curriculum and the faculty associated with each of the LLMs and see what appeals to you most.

I think that QMUL has a far better reputation especially for human rights and maritime law

QMUL is far better. SOAS is an interesting choice too.