Is it good to do Master's degree after completing B.Tech or Its better to accept the job offered after the B.Tech course ?

Hello!

Advantages of waiting 1-2 years:

1. Strenghten your resume & skillsets so that your post-MS job search becomes easy.
2. Make some money to stabilize your family and yourself.
3. Get more time to ace GRE/GATE and publish 1-2 papers in top conferences, so that you can get into a better school.

Advantages of doing immediately:

1. Your academic knowledge is hopefully fresh and you will find less of a pain to go to the classes, take tests and do assignments. People who are moving back from work often find it hard to readjust.
2. Your workplace is unlikely to add anything relevant to your MS academic curriculum. Unlike an MBA program, good MS programs are more academic and less related to job skills.
3. You are young with hopefully less commitments (relationships, family burdens) that will enable you to focus on research work better.
4. You have a much longer time to grow your post-Masters career.

In short, it is more advantageous to do the MS right out of college (if you want to do MS). If you like the research curriculum, you might even choose to continue doing your Phd. Working a couple of years is not going to significantly help with your MS work, if you already have an admit at a top school.