I just spoke to a retired U.S. Army Officer with extensive Islamic counterterrorism experience who told me the following:
Based on victimology profiles and "walking the cat backward," I would say the purpose of the attack was to inflict economic damage on India by scaring off Western investors and only incidentally to kill Jews who happened to be available easy targets. From their perspective killing Jews was just a free bonus to their economic objective of hurting the Indian governments domestic credibility.