It is desirable to have primers with GC contents between 50-60% but it does not mean that oligos with less GC can't be designed or employed successfully. We have amplified certain genes using primers with calculated Tm as low as 45C (primarily because GC contents were between 30-40%). 

I usually just make them a little longer and try to end the primer with a GC clamp.

Hello Sonu

As indicated by Austin you can make your primers longer. Most Oligos are between 18 and 22bp in length but there is no reason why fir example you could not add another 5bp

I would however pay particular attention to the last 5bp: Try not to include more than 3 G/C residues in those last 5bp but in your case where the primer might be AT rich end the primer in either a GG GC or CC residue to ensure efficient priming

For primers over 25bp or so remember to BLAST to verify that your primer only binds to your 1 target sequence of interest

Finally whilst I agree that primers can go as low as 45C with reference to annealing in general it is better to keep your annealing temp above 50C and ideally 55-65C for maximum likely hood of specificity; although in your case perhaps annealing above 50C would be more practicable than a higher temp in view of your AT content