Help with naming molecule
The suggested name 5-bromo-4-isopropyl-2-methylhex-2-ene is not wrong; however, it is not the preferred name according to current IUPAC recommendations.

Since the compound has a double bond but no principal characteristic group that would be expressed as a suffix, it is clear that the parent structure is a 2-methylhex-2-ene. However, there is a choice between two different principal chains, which lead to different names:  


5-bromo-2-methyl-4-(propan-2-yl)hex-2-ene and  
4-(1-bromoethyl)-2,5-dimethylhex-2-ene  


Both possible chains have two additional (but different) substituent groups in the same positions; therefore, the usual nomenclature criteria related to number and location of substituent groups do not help. Finally alphabetical order is used to identify the preferred name as 4-(1-bromoethyl)-2,5-dimethylhex-2-ene.