Is iodine a liquid? if yes then why bromine is only given as a liquid non-metal?

You can never say that any substance is a liquid, a solid, or a gas. Every substance you name can be all of those, depending on the TEMPERATURE.

At standard pressure . . .

-- Iodine is solid below 113.7°C, and gas above 184°C .

-- Bromine is solid below -7.2°C, and gas above 58.8°C .

-- "Room temperature" is considered to be the range from 20°C to 23.5°C.

-- Iodine is solid in that range.

-- Bromine one of only two elements that are known to be liquids AT
ROOM TEMPERATURE.  The other one is mercury ... a metal.

Explanation: The air inside the bulb is taken out and replaced with a gaseous mixture of argon and nitrogen which help ensure a longer-life for the filament. The bulb will be tested to make sure they're up to the job.