The relativistic mass is a confusing concept that should be avoided at all cost.
Physicists use the wording mass for the invariant mass or an object, or its rest mass. This consists of an intrinsic property of it.
What is abusively called the relativistic mass is nothing but another name for the energy of the object (divided by the speed of light squared). Therefore, it is better to use the wording energy instead.
I hope this clarifies.
RE: Einstein was right- Scientists proved Theory of relativity