Is it permissible to seek assistance from the Holy Quran to facilitate marriage to a young man whose mother rejects him, as she is likely practicing sorcery to separate them?

There is nothing that eases and facilitates matters like the fear of Allah (piety), as in His Almighty saying: "And whoever fears Allah - He will make for him ease in his affair." The young man mentioned is a stranger to you, and it is not permissible to establish a relationship with him outside the bounds of marriage. This relationship must be severed, and you should ask Allah to choose for you what is good, and to destine your marriage to him if there is good in it, and to avert him from you if there is evil in it. Remember that what was destined to befall you would not have missed you, and what missed you was not destined to befall you. Dreams and visions have no connection to istikhara.