IELTS

I am sorry, IELTS band of 4.5 is too low. You need at least 6 band, preferably 6.5 bands minimum to pursue any course at decent university abroad. With your score, your visa will get rejected.

Dear Khurminath,
Germany is the best country for mechanical engineering but your academic grades are not at par with German universities. USA on the other hand has the maximum universities which are globally known, you can check out university options in US, Australia and UK for your studies.
Remember

Yes, you can get admission.

Hi,
Kindly, check the listing on Shiksha website:
https://testprep.shiksha.com/ielts-exams-coaching-classes-in-delhi-ncr-categorypage-14-51-930-0-0-10223-1-2-0-none-1-0#cateSearchBlock

Of course, IELTS is accepted by UK and many countries, in fact preferred in UK. London for your information is not a country so you need to be specific where you want to apply. Canada is a better option as it offers work permits which is not available to international students in UK currently if you

Yes you can provide your IELTS scores for admission purposes, but check with the university website once if they accept IELTS scores or not. Most universities do accept them, so you should be fine.

5 band is a little low score. Even if you get accepted to a university with this score, you might face problems during your visa interview as the visa official may reject your application based on your IELTS band.

Germany and Poland are some good options. GMAT for your information is not an English proficiency test. However you can take GRE instead of GMAT for MBA admissions. Besides IELTS or TOEFL you can take PTE, CPE etc but check university websites for accepted English language tests. Requirements differ

Hi Vaibhavi,
Some of the popularly followed books include Target Band 7, IELTS Academic by Simone Braverman, The Official Cambridge Guide to IELTS, New Insight into IELTS, ETS: Official Guide to the TOEFL, Kaplan TOEFL iBT Premier and ETS: Official TOEFL iBT Tests to name a few.

IELTS scores are valid for 2 years and it is expected that it might extend to 3 years. So, you can ideally start 6 months or a year before to prepare and appear for the test.