The chances of getting admission to REC (Regional Engineering College) with a 47 percentile in JEE Mains and 87% in 12th, even as an EWS female student, are slim. RECs typically have higher cutoffs for admission.

However, the exact cutoffs can vary depending on several factors:

• State-specific cutoffs: RECs in different states may have varying cutoffs.
• Branch preference: Cutoffs for civil engineering might be higher compared to other branches.
• Number of applicants: The number of applicants for RECs can also influence cutoffs.

To improve your chances of admission, you might consider the following:

• Participate in the counseling process: Even if your rank is lower, participating in the counseling process might lead to unexpected opportunities.
• Explore other options: Consider other engineering colleges or branches that might be more accessible with your rank.
• Prepare for other entrance exams: If you're interested in pursuing engineering, consider preparing for other entrance exams like BITSAT or VITEEE.

While it's challenging to predict the exact outcome, it's advisable to explore all available options and participate in the counseling process.

I hope this information helps you.