What is this liquid called in my India ink?
India ink has only three ingredients: lampblack, water and gelatin or shellac as a binder(in fact, traditional India ink doesn't even contain this), with shellac being much more common. As you've guessed, this means that the clear liquid on top is probably a mixture of shellac and water.

Shellac can be found easily online (if you can't find it in person) either as flakes or a liquid.