In the General Theory of Relativity it is being introduced that the energy of motion is converted to the mass of that particle or matter or we can say that are interchangeable. It has a wide range use in the nuclear physics. The whole equation 𝑬 = 𝒎𝒄 𝟐 is a relativistic mass-energy equivalence and the term “mass” is also relativistic in nature. In special relativity, however, the energy of a body at rest is determined to be 𝒎𝒄 𝟐 . Thus, each body of rest mass m possesses 𝒎𝒄 𝟐 of “rest energy,” which potentially is available for conversion to other forms of energy. Here we initiated a equation from this if the Energy of motion has a vector form and it is in 3D space model as we know the energy of motion converted it to mass here we can do it by quantum mechanics. We think of that if the energy of motion is equal to the kinetic energy (time-independent equation from the Schrödinger equations) then we can solve the vector form of the energy and can find how much mass is being converted from the energy of motion(vector form). Here we have taken the kinetic energy from the Schrödinger equations not that from kinematics if we do then the speed of light will be equal to the velocity of that particle, which is violating the law of relativity thus I used the Schrödinger equations for simplicity .We got the equation and we have to do some calculation of the partial differentials and if the value of 𝑴′ is coming to be negative then the particle doesn’t exist and else we can find the mass converted and also the existence of that particle or matter of the universe. By this process, we can get the mass, the existence of matter/particle in this universe for that instance. We can use it if the energy is in the vector form and given some distance traveled in vacuum/air for some definite time we will get the desired result of mass.