You have any mobility in that teeth.
Gum swelling is due to accumulation of deposit in that area.your teeth are crowed.
Proper brushing that area up and down in rotating motion.
Scaling is the treatment plan.now a days nobody doing scaling.so homely remedy is the choice.
Next Steps
proper brushing
betadine gargle
if you have pain and swelling then take following medications
1.ciplox tz 1-0-1 5days
2.meftal fort 1-1-15days
3.OME PPI 1-0-0 5days(take 1/2hr before food
Health Tips
after proper cleaning that area subside that gingival swelling