Through FB! Insta doesn't allow follower oriented campaign like Facebook. However, post like campaigns if targeted and designed well, are very cheap, for engagement.

Run 4-5 post like campaigns for 7 days and add minimum INR 1000/- budget and see the difference after a week.

Keep Running the campaigns giving good results, and modify others according to the funnel ALGO used in others. Repeat for 4 weeks.

Pro Tip: Post multiple times in a day on Insta and see when your users are most active on different days of the week.

Follow some users with followers and following count which is balanced. E.g. 1500 followers and 1200 following. Send them personal message mentioning their usernames and ask them to follow back and grow together.
Best of luck!