Is it possible for me to miss claiming any inheritance offered by my grandparents?

I am not sure I get the drift of your question, but if you are concerned about your mother's intentional nondisclosure of your whereabouts as far as your grandfparents are concerned, then you should try immediately make contact and if that fails, contact a family law lawyer immediately to file a petition on your behalf to obtain a court order to allow to reunify with your grandparents, and prevent your mother from interfering in the establishment of that relationship.