According to Einstein's theory of relativity, the maximum velocity possible in the universe is the speed of light in a vacuum, denoted by the symbol 'c'. The speed of light is approximately 299,792,458 meters per second (or about 186,282 miles per second).
As an object with mass approaches the speed of light, its relativistic mass increases, which means that it requires more and more energy to accelerate it further. However, as the object's velocity approaches the speed of light, the amount of energy required to accelerate it becomes infinite. This implies that it is not possible for an object with mass to reach or exceed the speed of light.
Moreover, according to our current understanding of physics, there is no known theoretical maximum weight limit for an object. The concept of weight depends on the gravitational force acting on an object, and it is not directly related to an object's velocity. The relativistic effects such as time dilation and length contraction become significant as an object approaches the speed of light, but they do not impose an upper limit on an object's weight.
Therefore, the maximum velocity possible without violating Einstein's theory of relativity is the speed of light, and there is no theoretical maximum weight limit for an object.