If L(G1) is the language that is produced by grammar G1 and G1 is not LR(k) parsable (specifically speaking for k = 1). Does there exist a grammar Gx that is L(Gx) = L(G1) where Gx is LR(1) parsable ? If that is possible can it be generalized to all possible languages or just a subset?
You can mechanically transform an LR(k) grammar into an LR(1) grammar (source)
This is not true for LR(*) grammars (k=inf). However, that statement doesn't mean that there isn't such a grammar for the same language. You might just need to rewrite the grammar.
Grammars exist that cannot be transformed, however. Languages for Context-Sensitive grammars can be more expressive than context-free grammars (can only be recognized by linear-bounded automata). Therefore, your hoped-for translation is possible for just a subset.
Update for clarification:
There are languages that can not be represented by LR grammars but do have a grammar that is not LR (the language requires something more powerful than LR). There are also grammars that are not LR that recognize a language that can be recognized by an LR grammar (the language just happens to have a complex grammar, but it is not required).
Explanation 1: if you know which $k$ it shall be, you can easily check if the grammar is $LR(k)$ and thus derive an $LR(1)$ Grammar for it. On the other hand you cannot even know if there is a $k \geq 0$ such that $G$ is $LR(k)$.
Different with "Yes and No":
Yes: $L(G_1)$ is deterministic, then it is immediately $LR(k)$ and thus $LR(1)$. No: $L(G_1)$ is not deterministic. This means the language itself is inherently ambiguous this in turn means that there is no Grammar $G_n$ which is not ambiguous.
Much more and much more detailed (and quite understandable, far better than I am able right now) can be found in the following two works. The second contains (iirc) the proof that $LL(k)$ is a (theoretically) weaker than $LR(k)$.
Knuth, D. E. (1965). On the translation of languages from left to right.
D. J. Rosenkrantz and R. E. Stearns. 1969. Properties of deterministic top down grammars.