Dear Vidhya,
What is the nature of your industry? Does your company have skilled or unskilled labours? If you do not have labours then nothing wrong to make official language as English.
The important question is whether you have made a formal policy on official language. In many companies, especially MNCs, official language for communication is English. All the meetings and correspondence is done in English. However, that does not mean that speaking in local language has been banned as such. During celebration of cultural activities or festivals, local language is used for communication. Secondly, communication in vernacular language is done where it is necessary (like while dealing with the government officials) but preeminence of English is cherished at the same time.
Uniformity in communication helps bridging cultural gaps. Communication in English helps in maintaining a formal atmosphere in the office. This is also important. If you are from Chennai then making official language as English should not be a problem as such.
India is multi-linguist country. Polyglots like you are found more in south India. Nevertheless, if a communication in local language is permitted, it may form a informal group. This informal group could turn into pressure group and it could pose a challenge.
Thanks,
Dinesh Divekar