GC-MS, LC-MS etc. But for confirmation you have to go for NMR, UV, FT-IR.

Do TLC and compare the Rf to known compounds.

Together with the MS and UV results you may find what it is.

Firstly use IR thrn charaterize by GC and TLC

if your NMR results are not adding up, the compound may still have some impurities. You may need to double chack on that.

If your compound happens to be a crystalline solid, you may try X-ray diffraction. You can get the structure of the compound by single crystal X-ray diffraction, and then by powder X-ray diffraction you can verify its purity.

Solid or not, you must also do elemental analysis. This analysis allows us to narrow the number of possible structures that come from NMR and MS.

GC-MS, HPLC-MS, but finally you must perform NMR and FT_IR

run HPTLC ensure your compound is purified and try out other techniques such as x-ray, HPLC, GC etc