It appears that the Angolan Air Force is set to acquire six more Su-30Ks from Russia to increase it's fleet, during the just recent MAKS-2017 airshow the director of the Russian 558th aircraft repair plant (ARZ) Pavel Pinigin confirmed that Russians and Belarus are jointly searching for buyers for the mothballed Sukhois which was built to fulfill an Indian Air Force order in 1996.
According to him, in 2013 Angola made a request for the six fighter aircraft but has yet to receive it's order with the agreement stalled due to 'unfortunate complications'.
This particular batch of Su-30K was initially delivered to India on a temporary basis until the Su-30MKI (the Indian version) is developed. The aircraft were initially offered to Belarus, Sudan, Vietnam and Angola. However, the delay in delivery was due to the need to reconfigure the fighter planes to fulfill the Angolan Air Force's requirement and match its current Su-30MK fleet.
India had intended to upgrade these early aircraft but instead used them as part-exchange for new aircraft. The Angolan Air Force currently flies around half a dozen Su-27 Flankers