The idea I got from previous posts is that an RC network is not such a reliable idea , hence I was looking for a supervisor with dual capability of brown out detection and switch reset. MAX 709 which Christian sugested is not available in Mumbai and hence the best alternative is 1232.The same fate seems to have befallen 89C51RD2BN also as John mentioned.

By the way what problems does a RC network reset cause ? I saw that the board which Charles has put in one of his posts has the same.

Andy thanks for your inputs on power saving and battery choice.

Thomas