How to resolve registered area mistake

six years back my mother settled the property in her name to me and my elder brother.The detail is total area of land is 2800 sqft. Front side 1512.5 sqft. land with building in G.F & F.F Settled in my name. Back side vacant land( 1000sqft) and passage from road to backside and land for car parking totalling 1287.5 sqft registered in my brother's name.i have paid for the extra land and building . The area marking has been registered pictorially showing one single colour for the front portion and different colours for the passage,carparking and baskside land. But in my brother's EC the land area registered shows 1000sq ft instead of 1287.5 sqft. How this can be corrected . Is it problem due to different colouring for passage , carparking and vacant backside land.Please clarify and guide