Upper critical field and coefficient of magnetoresistance in NdBa2Cu3O7−y and NdBa2Cu2.9Mn0.1O7−y

► The magnetoresistance of Nd-123 and Mn doped Nd-123 has been studied. ► The upper critical field and coefficient of magnetoresistance have been extracted. ► Change in the coherence length has been observed. ► The impact of Mn substitution has been discussed.