My borewell water is salty, can I still use it to irrigate?

You may be able to use salty water, but it depends on how salty it is, so the first step is a water test that gives EC and the salt content. Mildly salty water can often be used with care, while very salty water damages the crop and builds salt in the soil over time. Ways to manage it include mixing the salty borewell water with better water like canal or rainwater to bring down the concentration, choosing crops and varieties that tolerate salt, giving enough water at a stretch so salts get washed below the roots rather than many small waterings, and keeping drainage good so salts can leave. Drip irrigation often handles salty water better than flood because it keeps the root zone moist and pushes salts to the edge of the wetted area. Add organic matter to help the soil. Get the water tested and ask your KVK or the irrigation department to read the report and tell you the safe level and suitable crops for your exact water, because the limits depend on your soil and crop too.