hi there!! firstly, congratulations on getting such a strong set of GCSEs and predicted grades! honestly, i think you can easily give it a shot. as you'll probably know UCL, Bath and KCL are Top 10 universities and according to the Complete University Guide; UCL ranks 6th, Kings ranks 8th and Bath ranks 9th for Economics. since your predicted grades are super strong, i think that can overcome the 6s, as it shows a huge improvement in your performance during A-levels. bear in mind that a lot of people applying to places like UCL will probably have really high GCSE grades, particularly for Economics which is VERY competitive but your GCSEs are commendable and there is no harm in giving it a shot. i got an offer from LSE with 2 5s, 4 8s, 4 7s (not for Econ) so you never know. have you met the GCSE requirement in Eng Lang & Maths? if so, then you can easily apply. if you make sure you have a cracking personal statement, you have a chance. just make sure you have at least 2 less competitive options as your back up. Complete University Guide is a great source for finding university options. i would also suggest speaking to your school and you could potentially email the admissions teams at the unis for more advice. good luck!!! <3