First of all congratulations on getting 87 percentile.

With an 87 percentile in the JEE Main and rank 188681, securing ECE or ME in the top NITs or IIITs will be difficult, particularly in the general category. But there is a possibility of making it in:

• Lower-rung NITs (particularly in home state quota, if one is eligible)
• State government institutions
• Private universities under JEE Main counseling

You can also seek possibilities in the CSAB special rounds or investigate colleges where the cut-off rank exceeds 180,000 in past years.