Visible light communication (VLC) is seeking a lot of attention in the recent years due to high bandwidth, low cost, ease of implementation. VLC can be used for illumination as well as communication at the same time. Light emitting diode (LED) acts as a transmitter for data transmission and photo detector is used at the receiver side. Intensity Modulation (IM) is used to convert electrical signal into optical signal where only real and positive signal need to be transmitted. Optical orthogonal frequency division multiplexing (O-OFDM) is used in the VLC to enhance the bandwidth limitation due to LED. Using OOFDM for VLC does not provide the massive connectivity in an multi-user environment. A Non orthogonal multiple access (NOMA) is the further expansion where user can use both the time and frequency resources but distinguished in power domain with successive interference cancellation (SIC) at the receiver to decode the signal of each user. Also, Asymmetrically clipped optical orthogonal frequency division multiplexing (ACO-OFDM) is used to get positive signal with enhanced spectral efficiency. The proposed method is evaluated analytically and using simulation in terms of bit error rate (BER).