$($a$)$ How will revenue be recognized in the following situations?

$($i$)$ Mr$.$ Gupta runs a tutorial centre for a professional course. He charges Rs $12000$ per student at the time of admission to the course. The duration of such a course is $5$ months. He started a batch of $400$ students on $01\mathrm{.}01\mathrm{.}2022.$ The current financial year being followed is $2021-2022.$

$($ii$)$ A$.$M$.$ Securities has sold $100$ shares of ABC Co$.$ at Rs $2500$ to Sujit in May, $2020$ on condition that all these shares are to be repurchased after $6$ months at Rs $2700.$