No. It is not clear. The sentence needs rewording:
The UN Human Rights Committee noted: "Effective measures should be taken to prevent any control over mass media that would restrict the universal right to freedom of information."
'that would restrict' is a restrictive clause (as opposed to non-restrictiive) and so requires 'that', not 'which'.
However, this is not a quote, but your paraphrase of some resolution, so you would need to change the wording to "noted that effective..."