Hello, for any type of Interview you should have to listen carefully first then you answer So Watch various english videos on YouTube for good listening. Then for both gd and pi you should be able to know what are dos and don'ts. Doing more and more practice you get confidence. Refer the following links for tips
http://www.bschool.careers360.com/articles/7-gd-tips-crack-b-schools-admissions
http://www.bschool.careers360.com/articles/pi-tips-8-keys-crack-personal-interview-for-b-school-admission
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