I have get integrated btech *mtech in mechanical engg ,what should i do ,should i take it ,and take only btech degree?

If you have option to do this the you can go for it , you can save one year from integrated degree , and college can also give option to choose integrated in 3 year becasue Mtech Syllabus you can study after 5 semester or in final year

Yes u should its vey good stream and all the best.