Hi
pratitidatta123I am Devmitra.
I have been delivering on Quants for a while now.
I have my two cents here-
If you plan to structure your prep with a clear deadline, please put a boundary to your prep with official materials.
The free content all over the net will only make you feel overwhelmed as the date of your test nears.
You can also do some research and consider strategic variables like your prep timeline, your current level(take a free official mock), score expectation, practicality of achieving the expected score under the timeline, your own flexibility of daily prep and plan accordingly before you start using any free material.
There is no dearth of free materials and some of them are really good.
But the questions are which one or which ones to chose from the free resources?, How much of their content is good?, and for how long will you need to continue learning to cover the content effectively that builds up the GMAT syllabus?
So, suggest you to do some research by using the materials yourself and measuring your progress with tests. Do not go by claims. Try it on yourself.
Let me know if you have any more questions
Happy to help
Devmitra Sen
GMAT Mentor