hi Prahlad,


"I have to use a 12mm dia 220V Normally open type proximity switch in one of my projects"

well you dont have to worry about that. these kind of sensors are available in india. they are of inductive type(to detect ferrus materials) and capacitive type(to detect non ferrus materials),optical sensors are also available.they are available as
1)2wire and
2)3wire.
for 2 wire sensor you connect your load in series with the sensor( max 30ma)and for 3 wire you connect the load to separate wire provided as output and the neutral wire.

you have to tell me what you want to detect so that it is easy for me to give you some more information.