HR As Career - Career In Hr

Dear Sir,
I am a B-tech in Biotechnology and have worked for two years as Sales Engineer in an ORGAINZATION I have completed my MBA with HR as specialization I want to make my career in HR please suggest me sir which sector i should focus and tell whether my B-tech in Biotechnology will create a hindrance in pursuing Career in HR

Well, matters if you have done B-tech, if you want to make your career in HR and already have done completed MBA in HR then it's really good to you and it will sure help you to to get some relevant HR job soon.
But for the advancement in HR, it would be good to you if you gain some knowledge and awareness of various HR and Payroll software. You can try free version of http://www.saralpayroll.com that is an advanced payroll software.

Appreciate your Interest to do HR job.But dont waste your experience as you gained as Sales engineer.You need to ensure is your goal is HR or anything else.Doing cross major is a good option but you need to follow your goal through Continous learning.

Dear Sir,
please tell me the sector where i should focus my carrer as HR

It depends.Based on your Skill sets you can choose any sector.
Ex-If you like to deal with educated people only you can choose an IT firm or any other FMCG Sector
or else if you are good enough to handle illiterate you can go for Manufacturing sector
All the best