Both I/P and O/P Devices

Can I connect both input and output devices to my bolt at time?

Yes.
For example LED’s are output devices and LDR Sensor is an input device.

So when I create a product, should I select I/P device or O/P device?

According to your need

I want to use led and ldr at a time.So should i give i/p or o/p device?

Use gpio pins declare them separately

Yes we can connect according to our need as ldr and led both are input and output devices respectively can be connected together at a time in bolt .