Can i fit a turbo onto a peugeot 205 1.8 diesel engine?

Look ye u dnt need to upgrade ur suspention brakes n that jjus maybe ur inlet n outlet manifolds mainli ur owt let and becoz its a puegot engine dnt set ur turbo higher than 18 psi

You can fit a turbo to just about any car, the problems lie in changing the inlet and exhaust manifolds to house the turbo of choice and supplying the turbo with oil and water to cool it, also if the car has a ECU getting it chipped to provide the right amount of fuel at the right time.
To be honest if you want a turbo car it is best to buy one with a turbo already fitted as it will probably cost you less to buy for example a Mitsubishi Colt Turbo (around £1500) than to fit a Garrett Turbo (around £3000 with fitting and manifolds) to your 205. Not to mention that the gearbox, brakes and suspension would need to be upgraded aswell.