Thank you so much brother

And, In these colleges which were best for cseFrom your point of view with 50 k rank 

How was the St joseph engineering college manglore in all categories

St. Josheps Mangalore is an average college and if I talk about placements then you can land onto a Mass recruiter from there.
Overall you will have opportunities there because, you will be surrounded by NIT Surathkal, where you can go for pool Placements apart from that Manipal is also there and NMAMIT is also there . So, companies comes to these colleges so there are chances that companies visiting these can visit St Joseph's too!
So, opportunities are there but you will have to raise your own bar to grab that.

Overall all private colleges are nearly same. You will have to work hard to grab opportunities.
But I will suggest you to choose colleges in Bangalore.
Because to be frank with 50K rank you won't get colleges with excellent placements. So Bangalore is full of opportunities for off campus placements.
So in that case college won't matter to you.
Then only your hard work will matter.
If you work hard there then you can land onto any good company based on your talent via off campus placements. College won't matter much there.
So choose Bangalore based colleges.

Ok brother surely I will choose one of the Banglore college.and perform my best.