I have an option to work in the HR function of a commercial Bank. However, I feel one should avoid working for a bank as it deals in something which is haram i.e. interest My parents view is that interest was made haram because in those days individuals used to exploit the poor through this but now banks lend usually to people who use the money to make more money so there is no exploitation. Please shed light on this issue.
Interest is Haram and I do not agree with your parents' view. In fact even at the time of the Prophet (sws) one of the main purposes of getting loan with interest was commercial as it is clearly mentioned in the Qur'an (30:39).
You are correct that working in banks (although may not be directly committing a haram transaction) is in fact helping and contributing to haram.
However, there is a point that needs to be taken into consideration before any decisions. The sad fact is that we are living in an era where the whole economy of the world is based on riba. This makes it sometimes impossible for us to live and lead a reasonable life without some how unintentionally contributing to riba.
Therefore, while we need to make sure that as much as possible we are avoiding riba based systems, we also need to appreciate that God does not want us to go through extreme difficulties in following the Shari'ah.
Accordingly, if you see that you will not be able to easily get a satisfying job if you turn this offer down, and that you will remain with no good job for a long period as a result, then under God's mercy, and with the intention of jumping to a different career as soon as an opportunity comes, you may accept the offer. However, if you think this is an offer among others to come and you only need to wait for the next one then it is better to avoid it.