ive have a steel sheated car port is their a coating that can be applied to ie it has several leeks

Yes, as long the material is not corroded to a point it has lost its structural integrity.  The product needs to be cleaned thoroughly prior to application of any coating material.  The type of coating that would be best for your needs will be determined by the condition, seam style, pitch and overhead exposure.  Some products are better under ponding water or high foliage conditions than others.