Majha
The partition split the Punjab Province (British India) into the two states of West Punjab (Punjab, Pakistan) and East Punjab. However, the historic Majha region is arguably still the same as before since the partition does not change the previous history of Punjab, therefore does not change the geography of the Majha region of the historic Punjab region.
Punjab Province (British India)
It encompassed the present day Indian states of Punjab, Haryana, Chandigarh, Delhi, and Himachal Pradesh (but excluding the former princely states which were later combined into the Patiala and East Punjab States Union) and the Pakistani regions of the Punjab, Islamabad Capital Territory and Khyber Pakhtunkhwa.