Not on such an old model. Check your power supply and check the requirements for the new card. New cards usually require more power than you have. A 10 yr old computer cannot run today's video cards. Save the money for a newer model. 

Re: Could I install a Amd Rx 550 4 gb on dell vostro 460-i5 version

psu is 350W, good enough for RX550. Use online psu calculator you need 324W only.

Contrary to what you might think, actually RX550 is too weak for i5-2400 on 1080p resolution 

Intel Core i5-2400 (Clock speed at 100%) with AMD Radeon RX 550 (Clock speed at 100%) x1 will produce 13.22% of GPU bottleneck on 1080p resolution. Everything over 10% is considered as bottleneck.