How to choose and design a waveform generator such that it generates signals of mentioned rms voltage, Vi and of frequency f given below?
There are a few ways:


Use a micro with an internal or external DAC. Something like the dsPIC33FJ64GP802 has a nice dual 16-bit DAC that goes up to 100kHz.  
Design an analogue oscillator, such as a Wien bridge or Phase shift oscillator, both suited for this type of application (or indeed a Hartley/Colpitts)  
By a dedicated DDS (Direct Digital Synthesis) IC or similar and use this.