Should I join Taxila Business School or RCM Bangalore or drop a year and prepare for better?

I think you should prepare for better. This option is however demanding but reliable. It requires you to give up a year, work extremely hard (because better B-schools are better for a reason), and persevere even in the face of uncertainty.

I would recommend that you first reflect on why you want to pursue an MBA. Most people pursue an MBA to get a better job.

Those who make it to the best B-Schools, go a step further:

• They truly understand why an MBA is necessary for their career.
• Also, in order to stand out in a highly competitive pool of applicants, the best B-Schools invariably attract year after year. They must have a strong narrative about who they are and why they want to do an MBA.
• You must also consider factors like fees; some of the best schools, such as ISB, are not relatively affordable and require a significant initial investment.

Talk to people who have graduated from your desired institute before taking a gap year. Determine for yourself whether those schools are a good fit for you. Weigh all these points, their benefits and drawbacks, and you'll discover that the decision you eventually make will be based on facts, logic, and, to some extent, intuition, rather than silliness.