The expected H-NMR of isovanilline will be -

~10 for Aldehyde proton

~5 for Phenolic proton

~3.5-4.0 for Methoxy proton

And among the Aromatic proton, proton para to -OH will be up field, and rest 2 meta proton will be down. But the one also ortho to -OMe will be relatively down field.