I'm 63 Years old and receiving SSI of $1680.00 per month it is very difficuly to live on this, can I apply for Retirement benefits? And much more will I be able to receive? I'm not able to work due to I need a kidney transplant.
I'm sorry to hear about your health problems.
You don't specify what type of benefits that you currently are receiving, so I'm not sure how to answer your question. If you are already receiving Social Security disability (SSDI) benefits, you could not get higher benefits by filing for Social Security retirement benefits. SSDI benefits are essentially the same as drawing your unreduced retirement benefit early because you are unable to work. And, you cannot get Social Security retirement and disability benefits for the same month.
However, if you are drawing some other type of benefit (e.g. widow(er)'s, etc.), then you may be able to file for reduced retirement benefits now. You could then be eligible for the higher of the 2 benefit rates, but not both. If that is your situation, though, there would likely be better options. You may want to consider running the maximization software available on this website in order to determine whether or not you have any other filing options.