yes that is correct . you are far from ur near dear ..so u r saying that you are missinig him so much ....as you are misiing him / her in present so it is right way to say .

the correct way is: Mai aap ko bahut mis karoongi or Mujhe aap ki bahut yaad aayegi.

Hi :) Main aapko miss (or yaad) karti hoon - Present Tense मैं आपको miss (or याद ) करती हूँ It Means - I miss you. But you want to say " I will miss you a lot " in future tense. It will be Main aapko bahut miss karoongi - मैं आपको बहुत miss करूँगी * Karoonga - करूँगा - If speaker is male. बहुत - bahut = a lot Hope it helps :)