Hello Rishiv,
Yes NITs have good records for placement in mechanical engineering. But this statement is true for only few NITs. However, quality of students are so good that they secure placement in off campus recruitment too. In overall condition, After IITs, NITs has better record of placement in mechanical engineering. NIT Surat, NIT Patna, NIT Trichy, NIT Warangal, MNIT Allahabad has very decent records.