We can select  taurine bulls for A2. So it seems A1A2 issue is a not a barrier if we need to upgrade indigenous cattle.

A1 A2 is a reality in the sense A1 milk upon proteolytic digestion yield beta casomorphine-7(BCM-7). Whether BCM-7 is a potential hazard to healthy person is a debate. But in infants and other vulnerable groups it may not be good.

Thank you sir. In indian scenario mostly jersey and hf are used for upgradation.and red sindhi is also used. 

Check the links below, they are from a Brazilian group of researchers working with dairy Gyr cows here in our country and they have identified a great number of cows with A2A2 beta casein alleles (text in portuguese), you can also contact them here on the researchgate. Bests.

http://www.aptaregional.sp.gov.br/acesse-os-artigos-pesquisa-e-tecnologia/edicao-2011/2011-julho-dezembro/1249-identificacao-de-alelos-para-o-gene-da-beta-caseina-na-raca-gir-leiteiro-1/file.html

http://sbmaonline.org.br/anais/ix/trabalhos/pdf/4TAN.pdf