Mri shows oblique nondisplaced tear posterior horn and body medial meniscus, medial meniscal protrusion into the medial gutter. will i need surgery?

Yes: With displacement into the medial gutter, it is usually very painful as it impinges between the tibial plateau and the mcl.

Surgery : Surgery is most likely needed to resolve your problem. Meniscus tears simply do not heal on their own, regardless of conservative treatment (including prolotherapy). It is possible that your symptoms of pain, etc will improve with time without surgery...But that doesn't mean the tear healed. In fact, the tear will most likely get bigger leading to additional damage if not taken care of soon.