About share for long time

I want to buy share for long time, so on which category should i choose, I am getting confuse with DAY and IOC.

Please help me

I guess you mean long-term.

This is just the order type.
DAY means the order can be executed when the price you have indicated is touched during the whole trading session.
IOC (immediate or cancel) which shoots the order to exchange with the limit price and if not executed gets canceled.