In the year 2019 the sc rank cutoff for JEE advanced in IIT Ropar was 1977 for mechanical engineering. The approximated rank vs marks chart is given below,

SC RANK VS MARKS OBTAINED

1                                     301

101                                 165

501                                 122

1001                               104

You can guess that with 70 marks there is less chance to get a rank within 2000. You need to score more than 80 to be among first 2000 in JEE Advanced SC rank list. Here is the link for previous years cut off for IIT Ropar:

https://engineering.careers360.com/articles/jee-advanced-cutoff-for-iit-ropar

Also check out your rank with JEE Advanced rank predictor:

https://engineering.careers360.com/articles/jee-advanced-rank-predictor

SUGGESTION: Don't think about marks and ranks. Do prepare with a target to give your best in exam hall. Your goal will take you wherever you want. Make your goal higher.

All the best!