Hey RohitSharma,
15 mins for every RC passage is DEFINITELY going to hurt your Verbal score. Before we talk GMAT Verbal plan of action, you've got to accept one cold hard fact: you MUST answer EVERY SINGLE VERBAL question. To do this, you MUST stay "on benchmark." This means you must know exactly where you should be at any given minute during the Verbal section and guess on as many questions as you need to so that you consistently stay "on track." Here's some benchmarks I suggest:
Time Left On Clock---->
Question Number
71 min------>3
61 min------>8
51 min------>13
41 min------>19
31 min------>24
21 min------>30
11 min------>35
5 min------->39
1 min------->41
Write these down and keep them in front of you for EVERY Verbal full-length section you do. If you're falling behind, practice "guess/attempt/guess/attempt" until you "catch up" to the benchmark. For example, if you noticed the clock said 41 minutes and you're only on question 15, you're about 4 questions behind. You'll guess on the next question without even reading it, spend 2 minutes on the second question, guess on the third question without even reading it, then spend 2 minutes on the fourth question. Continue this pattern until you're back on track with the benchmarks. Why do we do this? Because we know the GMAT penalizes "strings" of incorrect questions, and it's VITAL to try and get some correct answers mixed in there. BUT this also requires you to be disciplined and "walk away" from a Verbal question after 2 minutes....
For your RC skills to grow, you will need to practice a LOT, especially if English isn't your first language. I'd suggest at least 30 minutes of RC practice EVERY DAY.
How do you practice?
To start, here's the mandatory books you'll need to get:
GMAT Official Guide - 13th edition
GMAT Official Guide - Verbal review
You'll want to know the RC questions in this book backwards, forwards, and upside down.
Other books with lots of passages to practice:
Veritas Prep - Reading Comprehension Guide
Manhattan GMAT - RC Strategy Guide
Artistotle Prep - RC Grail
What do you DO with these passages? Learn how to make a "Passage Map"! Every tutor worth their salt with have a particular way of breaking down an RC passage. Here's the template I use:
T:
S:
1:
2:
3:
POV:
P:
These symbols stand for Topic, Scope, Function of 1st Paragraph, Function of 2nd Paragraph, Function of 3rd Paragraph, Author's Point of View, and Purpose.
Part of the problem is that right now you are reading the passage to understand all of the details, but Detail Questions are only one type of question on the GMAT. And here's a secret: you only need to understand the details that are asked about, and since we can't anticipate WHAT details we'll be asked about later, it's best just to "glide" over them in a cursory way and focus instead on the passage's STRUCTURE. You can always go back later and re-read the details. But it's too hard to go back and find the "Function" of a paragraph once you're moved past it.
I could go on for DAYS (and I have

) about the importance of a passage map, but you'll probably find it more helpful to see some example passage maps:
https://gmatrockstar.com/2014/01/17/gmat ... y-purpose/
https://gmatrockstar.com/2013/10/31/gmat ... f-the-day/
Notice how the Passage Map I make is NOT a summary. They're basically predictions to anticipated questions. We find the Purpose for "Main Idea" questions, just like we find the Functions for "Logical Structure" questions.
I'd also suggest reading some non-GMAT material as well. As you read these articles, do the following:
-Circle the topic
-Underline any transition words
-Write down the purpose of each paragraph
-Write down the author's point of view in your own words
-Write down the Main Idea in your own words
ALWAYS read with a pen in your hand, and always ask the million dollar question, "
Why is the author saying this?"
- NY Times book review (I really like this article's description of how to use these articles for practice:
https://smartestprep.wordpress.com/2010/ ... rehension/)
- Scientific American:
https://www.scientificamerican.com/
- The Economist:
https://www.economist.com/
- The Spectator:
https://www.spectator.co.uk/
- Forbes:
https://www.forbes.com/
Keep in mind that the GMAT RC is not "hard" because of it's incredibly advanced language. Most of it is readily comprehensible, although it may occasionally use unfamiliar scientific or business terminology. The challenge of RC lies in breaking down the rhetoric of the passage, and grasping not only what the author's argument is, but HOW he/she makes it.
Hope this helps, and good luck! RC is a challenge, but you're up to it! You just need to change how you read.