Hi Talha,
Master data related to PP / QM are managed at plant level and not at company code levels. You can have one or multiple plants under a company code and for each plant you need to create master data or extend the existing master data.
If you are copy creating a plant from exiting plant then most of the config parameters will get copied. You need to extend exiting master data to new plant code (example BOM, Routing Work center etc). You also need to extend inspection plant, MIC, code groups catalogs etc. If you have limited set of data, if can be carried out manually for its always recommended to create / change / extend master data using mass transaction of LSMW.
You can utilize the option of BDC, BAPI IDOCs etc based on the complexity of master data. The master data sequence is important as you need to have material master ready first and then other dependent mater data. For example you need to have workcenters created first so that same can be assigned to operations of Routing and so on.
If you already have extraction program, use them to extract data or else take the dump of IMP tables for master data (for example, BOM - MAST & STPO , STKO). Create or use existing LSMW objects for extend materials and test the same. Data Migration is very imp and should also follow test in D-Q -P process flow.
Regards,
Rohit